Broadcasting signal transmitting apparatus, broadcasting signal receiving apparatus, broadcasting signal transmitting method, and broadcasting signal receiving method

ABSTRACT

The present invention proposes a method for transmitting a broadcasting signal. The method for transmitting a broadcasting signal according to the present invention proposes a system that can support a next generation broadcasting service in an environment supporting next generation hybrid broadcasting which uses a terrestrial broadcasting network and an Internet network. Also, the present invention proposes an effective signaling scheme that can cover both the terrestrial broadcasting network and the Internet network in the environment that supports the next hybrid broadcasting.

TECHNICAL FIELD

The present invention relates to an apparatus for transmitting abroadcast signal, an apparatus for receiving a broadcast signal andmethods for transmitting and receiving a broadcast signal.

BACKGROUND ART

As analog broadcast signal transmission comes to an end, varioustechnologies for transmitting/receiving digital broadcast signals arebeing developed. A digital broadcast signal may include a larger amountof video/audio data than an analog broadcast signal and further includevarious types of additional data in addition to the video/audio data.

DISCLOSURE Technical Problem

That is, a digital broadcast system can provide HD (high definition)images, multichannel audio and various additional services. However,data transmission efficiency for transmission of large amounts of data,robustness of transmission/reception networks and network flexibility inconsideration of mobile reception equipment need to be improved fordigital broadcast.

Technical Solution

The present invention provides a system capable of effectivelysupporting future broadcast services in an environment supporting futurehybrid broadcasting using terrestrial broadcast networks and theInternet and related signaling methods.

Advantageous Effects

The present invention proposes a method of efficiently providing ahybrid broadcast using a broadcast network and the Internet.

The present invention proposes a method of providing app-basedenhancement based on an app for a basic broadcast service.

The present invention proposes a method of providing app-basedenhancement in sync with a broadcast service.

The present invention proposes an architecture according to variousprotocols between a PD and a CD and a communication method between thePD and CD and between apps according to the architecture.

The present invention proposes an architecture and a signaling methodfor efficiently delivering information such as ESG or EAS from a PD to aCD.

DESCRIPTION OF DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this application, illustrate embodiment(s) of the invention andtogether with the description serve to explain the principle of theinvention. In the drawings:

FIG. 1 is a diagram showing a protocol stack according to an embodimentof the present invention;

FIG. 2 is a diagram showing a service discovery procedure according toone embodiment of the present invention;

FIG. 3 is a diagram showing a low level signaling (LLS) table and aservice list table (SLT) according to one embodiment of the presentinvention;

FIG. 4 is a diagram showing a USBD and an S-TSID delivered through ROUTEaccording to one embodiment of the present invention;

FIG. 5 is a diagram showing a USBD delivered through an MMT according toone embodiment of the present invention;

FIG. 6 is a diagram showing link layer operation according to oneembodiment of the present invention;

FIG. 7 is a diagram showing a link mapping table (LMT) according to oneembodiment of the present invention;

FIG. 8 is a diagram showing a structure of a broadcast signaltransmission device of a next-generation broadcast service according toan embodiment of the present invention;

FIG. 9 is a writing operation of a time interleaver according to anembodiment of the present invention;

FIG. 10 is a block diagram of an interleaving address generatorincluding a main-PRBS generator and a sub-PRBS generator according toeach FFT mode, included in the frequency interleaver, according to anembodiment of the present invention;

FIG. 11 is a diagram showing an architecture of a process of launching aCD application according to an embodiment of the present invention;

FIG. 12 is a diagram showing an architecture for communication betweenan app and an app according to an embodiment of the present invention;

FIG. 13 is a diagram showing an architecture for performingcommunication from a CD app to a PD app according to an embodiment ofthe present invention;

FIG. 14 is a diagram showing a message structure for communicationbetween a CD app and a PD according to an embodiment of the presentinvention;

FIG. 15 is a diagram showing a service/content identification messageformat according to an embodiment of the present invention;

FIG. 16 is a diagram showing a current service information messageformat according to an embodiment of the present invention;

FIG. 17 is a diagram showing an ESG message format according to anembodiment of the present invention;

FIG. 18 is a diagram showing a media playback state message formataccording to an embodiment of the present invention;

FIG. 19 is a diagram showing an EA message according to an embodiment ofthe present invention;

FIG. 20 is a diagram showing a subscription related message and anotification message of a Websocket protocol in JSON schema according toan embodiment of the present invention;

FIG. 21 is a diagram showing delivery of electronic service guide (ESG)information through a broadcast network according to an embodiment ofthe present invention;

FIG. 22 is a diagram showing transport elated information included in anSGDD according to an embodiment of the present invention;

FIG. 23 is a diagram showing a service/content identification messageformat according to another embodiment of the present invention;

FIG. 24 is a diagram showing ESGRequesttype parameters which may be usedfor communication for ESG delivery according to another embodiment ofthe present invention;

FIG. 25 is a diagram showing a method of processing a broadcast serviceat a PD according to an embodiment of the present invention; and

FIG. 26 is a diagram showing a broadcast reception apparatus operatingas a PD according to an embodiment of the present invention.

BEST MODE

Reference will now be made in detail to the preferred embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings. The detailed description, which will be given below withreference to the accompanying drawings, is intended to explain exemplaryembodiments of the present invention, rather than to show the onlyembodiments that can be implemented according to the present invention.The following detailed description includes specific details in order toprovide a thorough understanding of the present invention. However, itwill be apparent to those skilled in the art that the present inventionmay be practiced without such specific details.

Although the terms used in the present invention are selected fromgenerally known and used terms, some of the terms mentioned in thedescription of the present invention have been selected by the applicantat his or her discretion, the detailed meanings of which are describedin relevant parts of the description herein. Furthermore, it is requiredthat the present invention is understood, not simply by the actual termsused but by the meanings of each term lying within.

The present invention provides apparatuses and methods for transmittingand receiving broadcast signals for future broadcast services. Futurebroadcast services according to an embodiment of the present inventioninclude a terrestrial broadcast service, a mobile broadcast service, anultra high definition television (UHDTV) service, etc. The presentinvention may process broadcast signals for the future broadcastservices through non-MIMO (Multiple Input Multiple Output) or MIMOaccording to one embodiment. A non-MIMO scheme according to anembodiment of the present invention may include a MISO (Multiple InputSingle Output) scheme, a SISO (Single Input Single Output) scheme, etc.

FIG. 1 is a diagram showing a protocol stack according to an embodimentof the present invention.

A service may be delivered to a receiver through a plurality of layers.First, a transmission side may generate service data. The service datamay be processed for transmission at a delivery layer of thetransmission side and the service data may be encoded into a broadcastsignal and transmitted over a broadcast or broadband network at aphysical layer.

Here, the service data may be generated in an ISO base media file format(BMFF). ISO BMFF media files may be used for broadcast/broadband networkdelivery, media encapsulation and/or synchronization format. Here, theservice data is all data related to the service and may include servicecomponents configuring a linear service, signaling information thereof,non real time (NRT) data and other files.

The delivery layer will be described. The delivery layer may provide afunction for transmitting service data. The service data may bedelivered over a broadcast and/or broadband network.

Broadcast service delivery may include two methods.

As a first method, service data may be processed in media processingunits (MPUs) based on MPEG media transport (MMT) and transmitted usingan MMT protocol (MMTP). In this case, the service data delivered usingthe MMTP may include service components for a linear service and/orservice signaling information thereof.

As a second method, service data may be processed into DASH segments andtransmitted using real time object delivery over unidirectionaltransport (ROUTE), based on MPEG DASH. In this case, the service datadelivered through the ROUTE protocol may include service components fora linear service, service signaling information thereof and/or NRT data.That is, the NRT data and non-timed data such as files may be deliveredthrough ROUTE.

Data processed according to MMTP or ROUTE protocol may be processed intoIP packets through a UDP/IP layer. In service data delivery over thebroadcast network, a service list table (SLT) may also be delivered overthe broadcast network through a UDP/IP layer. The SLT may be deliveredin a low level signaling (LLS) table. The SLT and LLS table will bedescribed later.

IP packets may be processed into link layer packets in a link layer. Thelink layer may encapsulate various formats of data delivered from ahigher layer into link layer packets and then deliver the packets to aphysical layer. The link layer will be described later.

In hybrid service delivery, at least one service element may bedelivered through a broadband path. In hybrid service delivery, datadelivered over broadband may include service components of a DASHformat, service signaling information thereof and/or NRT data. This datamay be processed through HTTP/TCP/IP and delivered to a physical layerfor broadband transmission through a link layer for broadbandtransmission.

The physical layer may process the data received from the delivery layer(higher layer and/or link layer) and transmit the data over thebroadcast or broadband network. A detailed description of the physicallayer will be given later.

The service will be described. The service may be a collection ofservice components displayed to a user, the components may be of variousmedia types, the service may be continuous or intermittent, the servicemay be real time or non real time, and a real-time service may include asequence of TV programs.

The service may have various types. First, the service may be a linearaudio/video or audio service having app based enhancement. Second, theservice may be an app based service, reproduction/configuration of whichis controlled by a downloaded application. Third, the service may be anESG service for providing an electronic service guide (ESG). Fourth, theservice may be an emergency alert (EA) service for providing emergencyalert information.

When a linear service without app based enhancement is delivered overthe broadcast network, the service component may be delivered by (1) oneor more ROUTE sessions or (2) one or more MMTP sessions.

When a linear service having app based enhancement is delivered over thebroadcast network, the service component may be delivered by (1) one ormore ROUTE sessions or (2) zero or more MMTP sessions. In this case,data used for app based enhancement may be delivered through a ROUTEsession in the form of NRT data or other files. In one embodiment of thepresent invention, simultaneous delivery of linear service components(streaming media components) of one service using two protocols may notbe allowed.

When an app based service is delivered over the broadcast network, theservice component may be delivered by one or more ROUTE sessions. Inthis case, the service data used for the app based service may bedelivered through the ROUTE session in the form of NRT data or otherfiles.

Some service components of such a service, some NRT data, files, etc.may be delivered through broadband (hybrid service delivery).

That is, in one embodiment of the present invention, linear servicecomponents of one service may be delivered through the MMT protocol. Inanother embodiment of the present invention, the linear servicecomponents of one service may be delivered through the ROUTE protocol.In another embodiment of the present invention, the linear servicecomponents of one service and NRT data (NRT service components) may bedelivered through the ROUTE protocol. In another embodiment of thepresent invention, the linear service components of one service may bedelivered through the MMT protocol and the NRT data (NRT servicecomponents) may be delivered through the ROUTE protocol. In theabove-described embodiments, some service components of the service orsome NRT data may be delivered through broadband. Here, the app basedservice and data regarding app based enhancement may be delivered overthe broadcast network according to ROUTE or through broadband in theform of NRT data. NRT data may be referred to as locally cached data.

Each ROUTE session includes one or more LCT sessions for wholly orpartially delivering content components configuring the service. Instreaming service delivery, the LCT session may deliver individualcomponents of a user service, such as audio, video or closed captionstream. The streaming media is formatted into a DASH segment.

Each MMTP session includes one or more MMTP packet flows for deliveringall or some of content components or an MMT signaling message. The MMTPpacket flow may deliver a component formatted into MPU or an MMTsignaling message.

For delivery of an NRT user service or system metadata, the LCT sessiondelivers a file based content item. Such content files may includeconsecutive (timed) or discrete (non-timed) media components of the NRTservice or metadata such as service signaling or ESG fragments. Systemmetadata such as service signaling or ESG fragments may be deliveredthrough the signaling message mode of the MMTP.

A receiver may detect a broadcast signal while a tuner tunes tofrequencies. The receiver may extract and send an SLT to a processingmodule. The SLT parser may parse the SLT and acquire and store data in achannel map. The receiver may acquire and deliver bootstrap informationof the SLT to a ROUTE or MMT client. The receiver may acquire and storean SLS. USBD may be acquired and parsed by a signaling parser.

FIG. 2 is a diagram showing a service discovery procedure according toone embodiment of the present invention.

A broadcast stream delivered by a broadcast signal frame of a physicallayer may carry low level signaling (LLS). LLS data may be carriedthrough payload of IP packets delivered to a well-known IP address/port.This LLS may include an SLT according to type thereof. The LLS data maybe formatted in the form of an LLS table. A first byte of every UDP/IPpacket carrying the LLS data may be the start of the LLS table. Unlikethe shown embodiment, an IP stream for delivering the LLS data may bedelivered to a PLP along with other service data.

The SLT may enable the receiver to generate a service list through fastchannel scan and provides access information for locating the SLS. TheSLT includes bootstrap information. This bootstrap information mayenable the receiver to acquire service layer signaling (SLS) of eachservice. When the SLS, that is, service signaling information, isdelivered through ROUTE, the bootstrap information may include an LCTchannel carrying the SLS, a destination IP address of a ROUTE sessionincluding the LCT channel and destination port information. When the SLSis delivered through the MMT, the bootstrap information may include adestination IP address of an MMTP session carrying the SLS anddestination port information.

In the shown embodiment, the SLS of service #1 described in the SLT isdelivered through ROUTE and the SLT may include bootstrap informationsIP1, dIP1 and dPort1 of the ROUTE session including the LCT channeldelivered by the SLS. The SLS of service #2 described in the SLT isdelivered through MMT and the SLT may include bootstrap informationsIP2, dIP2 and dPort2 of the MMTP session including the MMTP packet flowdelivered by the SLS.

The SLS is signaling information describing the properties of theservice and may include receiver capability information forsignificantly reproducing the service or providing information foracquiring the service and the service component of the service. Wheneach service has separate service signaling, the receiver acquiresappropriate SLS for a desired service without parsing all SLSs deliveredwithin a broadcast stream.

When the SLS is delivered through the ROUTE protocol, the SLS may bedelivered through a dedicated LCT channel of a ROUTE session indicatedby the SLT. In some embodiments, this LCT channel may be an LCT channelidentified by tsi=0. In this case, the SLS may include a user servicebundle description (USBD)/user service description (USD), service-basedtransport session instance description (S-TSID) and/or mediapresentation description (MPD).

Here, USBD/USD is one of SLS fragments and may serve as a signaling hubdescribing detailed description information of a service. The USBD mayinclude service identification information, device capabilityinformation, etc. The USBD may include reference information (URIreference) of other SLS fragments (S-TSID, MPD, etc.). That is, theUSBD/USD may reference the S-TSID and the MPD. In addition, the USBD mayfurther include metadata information for enabling the receiver to decidea transmission mode (broadcast/broadband network). A detaileddescription of the USBD/USD will be given below.

The S-TSID is one of SLS fragments and may provide overall sessiondescription information of a transport session carrying the servicecomponent of the service. The S-TSID may provide the ROUTE sessionthrough which the service component of the service is delivered and/ortransport session description information for the LCT channel of theROUTE session. The S-TSID may provide component acquisition informationof service components associated with one service. The S-TSID mayprovide mapping between DASH representation of the MPD and the tsi ofthe service component. The component acquisition information of theS-TSID may be provided in the form of the identifier of the associatedDASH representation and tsi and may or may not include a PLP ID in someembodiments. Through the component acquisition information, the receivermay collect audio/video components of one service and perform bufferingand decoding of DASH media segments. The S-TSID may be referenced by theUSBD as described above. A detailed description of the S-TSID will begiven below.

The MPD is one of SLS fragments and may provide a description of DASHmedia presentation of the service. The MPD may provide a resourceidentifier of media segments and provide context information within themedia presentation of the identified resources. The MPD may describeDASH representation (service component) delivered over the broadcastnetwork and describe additional DASH presentation delivered overbroadband (hybrid delivery). The MPD may be referenced by the USBD asdescribed above.

When the SLS is delivered through the MMT protocol, the SLS may bedelivered through a dedicated MMTP packet flow of the MMTP sessionindicated by the SLT. In some embodiments, the packet_id of the MMTPpackets delivering the SLS may have a value of 00. In this case, the SLSmay include a USBD/USD and/or MMT packet (MP) table.

Here, the USBD is one of SLS fragments and may describe detaileddescription information of a service as in ROUTE. This USBD may includereference information (URI information) of other SLS fragments. The USBDof the MMT may reference an MP table of MMT signaling. In someembodiments, the USBD of the MMT may include reference information ofthe S-TSID and/or the MPD. Here, the S-TSID is for NRT data deliveredthrough the ROUTE protocol. Even when a linear service component isdelivered through the MMT protocol, NRT data may be delivered via theROUTE protocol. The MPD is for a service component delivered overbroadband in hybrid service delivery. The detailed description of theUSBD of the MMT will be given below.

The MP table is a signaling message of the MMT for MPU components andmay provide overall session description information of an MMTP sessioncarrying the service component of the service. In addition, the MP tablemay include a description of an asset delivered through the MMTPsession. The MP table is streaming signaling information for MPUcomponents and may provide a list of assets corresponding to one serviceand location information (component acquisition information) of thesecomponents. The detailed description of the MP table may be defined inthe MMT or modified. Here, the asset is a multimedia data entity, iscombined by one unique ID, and may mean a data entity used to onemultimedia presentation. The asset may correspond to service componentsconfiguring one service. A streaming service component (MPU)corresponding to a desired service may be accessed using the MP table.The MP table may be referenced by the USBD as described above.

The other MMT signaling messages may be defined. Additional informationassociated with the service and the MMTP session may be described bysuch MMT signaling messages.

The ROUTE session is identified by a source IP address, a destination IPaddress and a destination port number. The LCT session is identified bya unique transport session identifier (TSI) within the range of a parentROUTE session. The MMTP session is identified by a destination IPaddress and a destination port number. The MMTP packet flow isidentified by a unique packet_id within the range of a parent MMTPsession.

In case of ROUTE, the S-TSID, the USBD/USD, the MPD or the LCT sessiondelivering the same may be referred to as a service signaling channel.In case of MMTP, the USBD/UD, the MMT signaling message or the packetflow delivering the same may be referred to as a service signalingchannel.

Unlike the shown embodiment, one ROUTE or MMTP session may be deliveredover a plurality of PLPs. That is, one service may be delivered throughone or more PLPs. Unlike the shown embodiment, in some embodiments,components configuring one service may be delivered through differentROUTE sessions. In addition, in some embodiments, components configuringone service may be delivered through different MMTP sessions. In someembodiments, components configuring one service may be divided anddelivered in a ROUTE session and an MMTP session. Although not shown,components configuring one service may be delivered through broadband(hybrid delivery).

FIG. 3 is a diagram showing a low level signaling (LLS) table and aservice list table (SLT) according to one embodiment of the presentinvention.

One embodiment t3010 of the LLS table may include information accordingto an LLS_table_id field, a provider_id field, an LLS_table_versionfield and/or an LLS_table_id field.

The LLS_table_id field may identify the type of the LLS table, and theprovider_id field may identify a service provider associated withservices signaled by the LLS table. Here, the service provider is abroadcaster using all or some of the broadcast streams and theprovider_id field may identify one of a plurality of broadcasters whichis using the broadcast streams. The LLS_table_version field may providethe version information of the LLS table.

According to the value of the LLS_table_id field, the LLS table mayinclude one of the above-described SLT, a rating region table (RRT)including information on a content advisory rating, SystemTimeinformation for providing information associated with a system time, acommon alert protocol (CAP) message for providing information associatedwith emergency alert. In some embodiments, the other information may beincluded in the LLS table.

One embodiment t3020 of the shown SLT may include an @bsid attribute, an@sltCapabilities attribute, an sltInetUrl element and/or a Serviceelement. Each field may be omitted according to the value of the shownUse column or a plurality of fields may be present.

The @bsid attribute may be the identifier of a broadcast stream. The@sltCapabilities attribute may provide capability information requiredto decode and significantly reproduce all services described in the SLT.The sltInetUrl element may provide base URL information used to obtainservice signaling information and ESG for the services of the SLT overbroadband. The sltInetUrl element may further include an @urlTypeattribute, which may indicate the type of data capable of being obtainedthrough the URL.

The Service element may include information on services described in theSLT, and the Service element of each service may be present. The Serviceelement may include an @serviceId attribute, an @sltSvcSeqNum attribute,an @protected attribute, an @majorChannelNo attribute, an@minorChannelNo attribute, an @serviceCategory attribute, an@shortServiceName attribute, an @hidden attribute, an@broadbandAccessRequired attribute, an @svcCapabilities attribute, aBroadcastSvcSignaling element and/or an svcInetUrl element.

The @serviceId attribute is the identifier of the service and the@sltSvcSeqNum attribute may indicate the sequence number of the SLTinformation of the service. The @protected attribute may indicatewhether at least one service component necessary for significantreproduction of the service is protected. The @majorChannelNo attributeand the @minorChannelNo attribute may indicate the major channel numberand minor channel number of the service, respectively.

The @serviceCategory attribute may indicate the category of the service.The category of the service may include a linear A/V service, a linearaudio service, an app based service, an ESG service, an EAS service,etc. The @shortServiceName attribute may provide the short name of theservice. The @hidden attribute may indicate whether the service is fortesting or proprietary use. The @broadbandAccessRequired attribute mayindicate whether broadband access is necessary for significantreproduction of the service. The @svcCapabilities attribute may providecapability information necessary for decoding and significantreproduction of the service.

The BroadcastSvcSignaling element may provide information associatedwith broadcast signaling of the service. This element may provideinformation such as location, protocol and address with respect tosignaling over the broadcast network of the service. Details thereofwill be described below.

The svcInetUrl element may provide URL information for accessing thesignaling information of the service over broadband. The sltInetUrlelement may further include an @urlType attribute, which may indicatethe type of data capable of being obtained through the URL.

The above-described BroadcastSvcSignaling element may include an@slsProtocol attribute, an @slsMajorProtocolVersion attribute, an@slsMinorProtocolVersion attribute, an @slsPlpId attribute, an@slsDestinationIpAddress attribute, an @slsDestinationUdpPort attributeand/or an @slsSourceIpAddress attribute.

The @slsProtocol attribute may indicate the protocol used to deliver theSLS of the service (ROUTE, MMT, etc.). The @slsMajorProtocolVersionattribute and the @slsMinorProtocolVersion attribute may indicate themajor version number and minor version number of the protocol used todeliver the SLS of the service, respectively.

The @slsPlpId attribute may provide a PLP identifier for identifying thePLP delivering the SLS of the service. In some embodiments, this fieldmay be omitted and the PLP information delivered by the SLS may bechecked using a combination of the information of the below-describedLMT and the bootstrap information of the SLT.

The @slsDestinationIpAddress attribute, the @slsDestinationUdpPortattribute and the @slsSourceIpAddress attribute may indicate thedestination IP address, destination UDP port and source IP address ofthe transport packets delivering the SLS of the service, respectively.These may identify the transport session (ROUTE session or MMTP session)delivered by the SLS. These may be included in the bootstrapinformation.

FIG. 4 is a diagram showing a USBD and an S-TSID delivered through ROUTEaccording to one embodiment of the present invention.

One embodiment t4010 of the shown USBD may have a bundleDescription rootelement. The bundleDescription root element may have auserServiceDescription element. The userServiceDescription element maybe an instance of one service.

The userServiceDescription element may include an @globalServiceIDattribute, an @serviceId attribute, an @serviceStatus attribute, an@fullMPDUri attribute, an @sTSIDUri attribute, a name element, aserviceLanguage element, a capabilityCode element and/or adeliveryMethod element. Each field may be omitted according to the valueof the shown Use column or a plurality of fields may be present.

The @globalServiceID attribute is the globally unique identifier of theservice and may be used for link with ESG data(Service@globalServiceID). The @serviceId attribute is a referencecorresponding to the service entry of the SLT and may be equal to theservice ID information of the SLT. The @serviceStatus attribute mayindicate the status of the service. This field may indicate whether theservice is active or inactive.

The @fullMPDUri attribute may reference the MPD fragment of the service.The MPD may provide a reproduction description of a service componentdelivered over the broadcast or broadband network as described above.The @sTSIDUri attribute may reference the S-TSID fragment of theservice. The S-TSID may provide parameters associated with access to thetransport session carrying the service as described above.

The name element may provide the name of the service. This element mayfurther include an @lang attribute and this field may indicate thelanguage of the name provided by the name element. The serviceLanguageelement may indicate available languages of the service. That is, thiselement may arrange the languages capable of being provided by theservice.

The capabilityCode element may indicate capability or capability groupinformation of a receiver necessary to significantly reproduce theservice. This information is compatible with capability informationformat provided in service announcement.

The deliveryMethod element may provide transmission related informationwith respect to content accessed over the broadcast or broadband networkof the service. The deliveryMethod element may include abroadcastAppService element and/or a unicastAppService element. Each ofthese elements may have a basePattern element as a sub element.

The broadcastAppService element may include transmission associatedinformation of the DASH representation delivered over the broadcastnetwork. The DASH representation may include media components over allperiods of the service presentation.

The basePattern element of this element may indicate a character patternused for the receiver to perform matching with the segment URL. This maybe used for a DASH client to request the segments of the representation.Matching may imply delivery of the media segment over the broadcastnetwork.

The unicastAppService element may include transmission relatedinformation of the DASH representation delivered over broadband. TheDASH representation may include media components over all periods of theservice media presentation.

The basePattern element of this element may indicate a character patternused for the receiver to perform matching with the segment URL. This maybe used for a DASH client to request the segments of the representation.Matching may imply delivery of the media segment over broadband.

One embodiment t4020 of the shown S-TSID may have an S-TSID rootelement. The S-TSID root element may include an @serviceId attributeand/or an RS element. Each field may be omitted according to the valueof the shown Use column or a plurality of fields may be present.

The @serviceId attribute is the identifier of the service and mayreference the service of the USBD/USD. The RS element may describeinformation on ROUTE sessions through which the service components ofthe service are delivered. According to the number of ROUTE sessions, aplurality of elements may be present. The RS element may further includean @bsid attribute, an @sIpAddr attribute, an @dIpAddr attribute, an@dport attribute, an @PLPID attribute and/or an LS element.

The @bsid attribute may be the identifier of a broadcast stream in whichthe service components of the service are delivered. If this field isomitted, a default broadcast stream may be a broadcast stream includingthe PLP delivering the SLS of the service. The value of this field maybe equal to that of the @bsid attribute.

The @sIpAddr attribute, the @dIpAddr attribute and the @dport attributemay indicate the source IP address, destination IP address anddestination UDP port of the ROUTE session, respectively. When thesefields are omitted, the default values may be the source address,destination IP address and destination UDP port values of the currentROUTE session delivering the SLS, that is, the S-TSID. This field maynot be omitted in another ROUTE session delivering the servicecomponents of the service, not in the current ROUTE session.

The @PLPID attribute may indicate the PLP ID information of the ROUTEsession. If this field is omitted, the default value may be the PLP IDvalue of the current PLP delivered by the S-TSID. In some embodiments,this field is omitted and the PLP ID information of the ROUTE sessionmay be checked using a combination of the information of thebelow-described LMT and the IP address/UDP port information of the RSelement.

The LS element may describe information on LCT channels through whichthe service components of the service are transmitted. According to thenumber of LCT channel, a plurality of elements may be present. The LSelement may include an @tsi attribute, an @PLPID attribute, an @bwattribute, an @startTime attribute, an @endTime attribute, a SrcFlowelement and/or a RepairFlow element.

The @tsi attribute may indicate the tsi information of the LCT channel.Using this, the LCT channels through which the service components of theservice are delivered may be identified. The @PLPID attribute mayindicate the PLP ID information of the LCT channel. In some embodiments,this field may be omitted. The @bw attribute may indicate the maximumbandwidth of the LCT channel. The @startTime attribute may indicate thestart time of the LCT session and the @endTime attribute may indicatethe end time of the LCT channel.

The SrcFlow element may describe the source flow of ROUTE. The sourceprotocol of ROUTE is used to transmit a delivery object and at least onesource flow may be established within one ROUTE session. The source flowmay deliver associated objects as an object flow.

The RepairFlow element may describe the repair flow of ROUTE. Deliveryobjects delivered according to the source protocol may be protectedaccording to forward error correction (FEC) and the repair protocol maydefine an FEC framework enabling FEC protection.

FIG. 5 is a diagram showing a USBD delivered through MMT according toone embodiment of the present invention.

One embodiment of the shown USBD may have a bundleDescription rootelement. The bundleDescription root element may have auserServiceDescription element. The userServiceDescription element maybe an instance of one service.

The userServiceDescription element may include an @globalServiceIDattribute, an @serviceId attribute, a Name element, a serviceLanguageelement, a contentAdvisoryRating element, a Channel element, ampuComponent element, a routeComponent element, a broadbandComponentelement and/or a ComponentInfo element. Each field may be omittedaccording to the value of the shown Use column or a plurality of fieldsmay be present.

The @globalServiceID attribute, the @serviceId attribute, the Nameelement and/or the serviceLanguage element may be equal to the fields ofthe USBD delivered through ROUTE. The contentAdvisoryRating element mayindicate the content advisory rating of the service. This information iscompatible with content advisory rating information format provided inservice announcement. The Channel element may include informationassociated with the service. A detailed description of this element willbe given below.

The mpuComponent element may provide a description of service componentsdelivered as the MPU of the service. This element may further include an@mmtPackageId attribute and/or an @nextMmtPackageId attribute. The@mmtPackageId attribute may reference the MMT package of the servicecomponents delivered as the MPU of the service. The @nextMmtPackageIdattribute may reference an MMT package to be used after the MMT packagereferenced by the @mmtPackageId attribute in terms of time. Through theinformation of this element, the MP table may be referenced.

The routeComponent element may include a description of the servicecomponents of the service. Even when linear service components aredelivered through the MMT protocol, NRT data may be delivered accordingto the ROUTE protocol as described above. This element may describeinformation on such NRT data. A detailed description of this elementwill be given below.

The broadbandComponent element may include the description of theservice components of the service delivered over broadband. In hybridservice delivery, some service components of one service or other filesmay be delivered over broadband. This element may describe informationon such data. This element may further an @fullMPDUri attribute. Thisattribute may reference the MPD describing the service componentdelivered over broadband. In addition to hybrid service delivery, thebroadcast signal may be weakened due to traveling in a tunnel and thusthis element may be necessary to support handoff between broadband andbroadband. When the broadcast signal is weak, the service component isacquired over broadband and, when the broadcast signal becomes strong,the service component is acquired over the broadcast network to secureservice continuity.

The ComponentInfo element may include information on the servicecomponents of the service. According to the number of service componentsof the service, a plurality of elements may be present. This element maydescribe the type, role, name, identifier or protection of each servicecomponent. Detailed information of this element will be described below.

The above-described Channel element may further include an @serviceGenreattribute, an @serviceIcon attribute and/or a ServiceDescriptionelement. The @serviceGenre attribute may indicate the genre of theservice and the @serviceIcon attribute may include the URL informationof the representative icon of the service. The ServiceDescriptionelement may provide the service description of the service and thiselement may further include an @serviceDescrText attribute and/or an@serviceDescrLang attribute. These attributes may indicate the text ofthe service description and the language used in the text.

The above-described routeComponent element may further include an@sTSIDUri attribute, an @sTSIDDestinationIpAddress attribute, an@sTSIDDestinationUdpPort attribute, an @sTSIDSourceIpAddress attribute,an @sTSIDMajorProtocolVersion attribute and/or an@sTSIDMinorProtocolVersion attribute.

The @sTSIDUri attribute may reference an S-TSID fragment. This field maybe equal to the field of the USBD delivered through ROUTE. This S-TSIDmay provide access related information of the service componentsdelivered through ROUTE. This S-TSID may be present for NRT datadelivered according to the ROUTE protocol in a state of deliveringlinear service component according to the MMT protocol.

The @sTSIDDestinationIpAddress attribute, the @sTSIDDestinationUdpPortattribute and the @sTSIDSourceIpAddress attribute may indicate thedestination IP address, destination UDP port and source IP address ofthe transport packets carrying the above-described S-TSID. That is,these fields may identify the transport session (MMTP session or theROUTE session) carrying the above-described S-TSID.

The @sTSIDMajorProtocolVersion attribute and the@sTSIDMinorProtocolVersion attribute may indicate the major versionnumber and minor version number of the transport protocol used todeliver the above-described S-TSID, respectively.

The above-described ComponentInfo element may further include an@componentType attribute, an @componentRole attribute, an@componentProtectedFlag attribute, an @componentId attribute and/or an@componentName attribute.

The @componentType attribute may indicate the type of the component. Forexample, this attribute may indicate whether the component is an audio,video or closed caption component. The @componentRole attribute mayindicate the role of the component. For example, this attribute mayindicate main audio, music, commentary, etc. if the component is anaudio component. This attribute may indicate primary video if thecomponent is a video component. This attribute may indicate a normalcaption or an easy reader type if the component is a closed captioncomponent.

The @componentProtectedFlag attribute may indicate whether the servicecomponent is protected, for example, encrypted. The @componentIdattribute may indicate the identifier of the service component. Thevalue of this attribute may be the asset_id (asset ID) of the MP tablecorresponding to this service component. The @componentName attributemay indicate the name of the service component.

FIG. 6 is a diagram showing link layer operation according to oneembodiment of the present invention.

The link layer may be a layer between a physical layer and a networklayer. A transmission side may transmit data from the network layer tothe physical layer and a reception side may transmit data from thephysical layer to the network layer (t6010). The purpose of the linklayer is to compress (abstract) all input packet types into one formatfor processing by the physical layer and to secure flexibility andexpandability of an input packet type which is not defined yet. Inaddition, the link layer may provide option for compressing(abstracting) unnecessary information of the header of input packets toefficiently transmit input data. Operation such as overhead reduction,encapsulation, etc. of the link layer is referred to as a link layerprotocol and packets generated using this protocol may be referred to aslink layer packets. The link layer may perform functions such as packetencapsulation, overhead reduction and/or signaling transmission.

At the transmission side, the link layer (ALP) may perform an overheadreduction procedure with respect to input packets and then encapsulatethe input packets into link layer packets. In addition, in someembodiments, the link layer may perform encapsulation into the linklayer packets without performing the overhead reduction procedure. Dueto use of the link layer protocol, data transmission overhead on thephysical layer may be significantly reduced and the link layer protocolaccording to the present invention may provide IP overhead reductionand/or MPEG-2 TS overhead reduction.

When the shown IP packets are input as input packets (t6010), the linklayer may sequentially perform IP header compression, adaptation and/orencapsulation. In some embodiments, some processes may be omitted. Forexample, the RoHC module may perform IP packet header compression toreduce unnecessary overhead. Context information may be extractedthrough the adaptation procedure and transmitted out of band. The IPheader compression and adaption procedure may be collectively referredto as IP header compression. Thereafter, the IP packets may beencapsulated into link layer packets through the encapsulationprocedure.

When MPEG 2 TS packets are input as input packets, the link layer maysequentially perform overhead reduction and/or an encapsulationprocedure with respect to the TS packets. In some embodiments, someprocedures may be omitted. In overhead reduction, the link layer mayprovide sync byte removal, null packet deletion and/or common headerremoval (compression). Through sync byte removal, overhead reduction of1 byte may be provided per TS packet. Null packet deletion may beperformed in a manner in which reinsertion is possible at the receptionside. In addition, deletion (compression) may be performed in a mannerin which common information between consecutive headers may be restoredat the reception side. Some of the overhead reduction procedures may beomitted. Thereafter, through the encapsulation procedure, the TS packetsmay be encapsulated into link layer packets. The link layer packetstructure for encapsulation of the TS packets may be different from thatof the other types of packets.

First, IP header compression will be described.

The IP packets may have a fixed header format but some informationnecessary for a communication environment may be unnecessary for abroadcast environment. The link layer protocol may compress the headerof the IP packet to provide a mechanism for reducing broadcast overhead.

IP header compression may include a header compressor/decompressorand/or an adaptation module. The IP header compressor (RoHC compressor)may reduce the size of each IP packet based on a RoHC method. Then,adaptation module may extract context information and generate signalinginformation from each packet stream. A receiver may parse signalinginformation related to a corresponding packet stream and attach thecontext information to the packet stream. The RoHC decompressor mayrecover a packet header to reconfigure an original IP packet.Hereinafter, IP header compression may refer to only IP headercompressor via header compressor and may be a concept that combines IPheader compression and the adaptation procedure by the adaptationmodule. This may be the same as in decompressing.

Hereinafter, adaptation will be described.

In transmission of a single-direction link, when the receiver does nothave context information, the decompressor cannot restore the receivedpacket header until complete context is received. This may lead tochannel change delay and turn-on delay. Accordingly, through theadaptation function, configuration parameters and context informationbetween the compressor and the decompressor may be transmitted out ofband. The adaptation function may construct link layer signaling usingcontext information and/or configuration parameters. The adaptationfunction may periodically transmit link layer signaling through eachphysical frame using a previous configuration parameter and/or contextinformation.

Context information is extracted from the compressed IP packets andvarious methods may be used according to adaptation mode.

Mode #1 refers to a mode in which no operation is performed with respectto the compressed packet stream and an adaptation module operates as abuffer.

Mode #2 refers to a mode in which an IR packet is detected from acompressed packet stream to extract context information (static chain).After extraction, the IR packet is converted into an IR-DYN packet andthe IR-DYN packet may be transmitted in the same order within the packetstream in place of an original IR packet.

Mode #3 (t6020) refers to a mode in which IR and IR-DYN packets aredetected from a compressed packet stream to extract context information.A static chain and a dynamic chain may be extracted from the IR packetand a dynamic chain may be extracted from the IR-DYN packet. Afterextraction, the IR and IR-DYN packets are converted into normalcompression packets. The converted packets may be transmitted in thesame order within the packet stream in place of original IR and IR-DYNpackets.

In each mode, the context information is extracted and the remainingpackets may be encapsulated and transmitted according to the link layerpacket structure for the compressed IP packets. The context informationmay be encapsulated and transmitted according to the link layer packetstructure for signaling information, as link layer signaling.

The extracted context information may be included in a RoHC-Udescription table (RDT) and may be transmitted separately from the RoHCpacket flow. Context information may be transmitted through a specificphysical data path along with other signaling information. The specificphysical data path may mean one of normal PLPs, a PLP in which low levelsignaling (LLS) is delivered, a dedicated PLP or an L1 signaling path.Here, the RDT may be context information (static chain and/or dynamicchain) and/or signaling information including information associatedwith header compression. In some embodiments, the RDT may be transmittedwhenever context information is changed. In some embodiments, the RDTmay be transmitted in every physical frame. To transmit the RDT in everyphysical frame, a previous RDT may be re-used.

The receiver may select a first PLP and first acquire signalinginformation of the SLT, the RDT, etc., prior to acquisition of a packetstream. Upon acquiring the signaling information, the receiver maycombine the information to acquire mapping of service-IPinformation-context information-PLP. That is, the receiver may recognizeIP streams through which a service is transmitted, IP streamstransmitted through a PLP, and so on and acquire corresponding contextinformation of the PLPs. The receiver may select a PLP for delivery of aspecific packet stream and decode the PLP. The adaptation module mayparse the context information and combine the context information withthe compressed packets. Thereby, the packet stream may be recovered andtransmitted to the RoHC de compressor. Then, decompression may bestarted. In this case, the receiver may detect an IR packet and startdecompression from a first received IR packet according to an adaptationmode (mode 1), may detect an IR-DYN packet and start decompression froma first received IR-DYN packet (mode 2), or may start decompression fromany general compressed packet (mode 3).

Hereinafter, packet encapsulation will be described.

The link layer protocol may encapsulate all types of input packets suchas IP packets, TS packets, etc. into link layer packets. To this end,the physical layer processes only one packet format independently of theprotocol type of the network layer (here, an MPEG-2 TS packet isconsidered as a network layer packet). Each network layer packet orinput packet is modified into the payload of a generic link layerpacket.

In the packet encapsulation procedure, segmentation may be used. If thenetwork layer packet is too large to be processed in the physical layer,the network layer packet may be segmented into two or more segments. Thelink layer packet header may include fields for segmentation of thetransmission side and recombination of the reception side. Each segmentmay be encapsulated into the link layer packet in the same order as theoriginal location.

In the packet encapsulation procedure, concatenation may also be used.If the network layer packet is sufficiently small such that the payloadof the link layer packet includes several network layer packets,concatenation may be performed. The link layer packet header may includefields for performing concatenation. In concatenation, the input packetsmay be encapsulated into the payload of the link layer packet in thesame order as the original input order.

The link layer packet may include a header and a payload. The header mayinclude a base header, an additional header and/or an optional header.The additional header may be further added according to situation suchas concatenation or segmentation and the additional header may includefields suitable for situations. In addition, for delivery of theadditional information, the optional header may be further included.Each header structure may be pre-defined. As described above, if theinput packets are TS packets, a link layer header having packetsdifferent from the other packets may be used.

Hereinafter, link layer signaling will be described.

Link layer signaling may operate at a level lower than that of the IPlayer. The reception side may acquire link layer signaling faster thanIP level signaling of the LLS, the SLT, the SLS, etc. Accordingly, linklayer signaling may be acquired before session establishment.

Link layer signaling may include internal link layer signaling andexternal link layer signaling. Internal link layer signaling may besignaling information generated at the link layer. This includes theabove-described RDT or the below-described LMT. External link layersignaling may be signaling information received from an external module,an external protocol or a higher layer. The link layer may encapsulatelink layer signaling into a link layer packet and deliver the link layerpacket. A link layer packet structure (header structure) for link layersignaling may be defined and link layer signaling information may beencapsulated according to this structure.

FIG. 7 is a diagram showing a link mapping table (LMT) according to oneembodiment of the present invention.

The LMT may provide a list of higher layer sessions carried through thePLP. In addition, the LMT may provide additional information forprocessing link layer packets carrying the higher layer sessions. Here,the higher layer session may be referred to as multicast. Information onIP streams or transport sessions transmitted through one PLP may beacquired through the LMT. In contrast, information on through which PLPa specific transport session is delivered may be acquired.

The LMT may be transmitted through any PLP identified to deliver theLLS. Here, the PLP for delivering the LLS may be identified by an LLSflag of L1 detail signaling information of a physical layer. The LLSflag may be a flag field indicating whether the LLS is transmittedthrough a corresponding PLP with respect to each PLP. Here, the L1detail signaling information may be correspond to PLS2 data which willbe described later.

That is, the LMT may also be transmitted through the same PLP along withthe LLS. Each LMT may describe mapping between PLPs and IP address/portas described above. As described above, the LLS may include an SLT and,in this regard, the IP address/ports described by the LMT may be any IPaddress/ports related to any service, described by the SLT transmittedthrough the PLP such as a corresponding LMT.

In some embodiments, the PLP identifier information in theabove-described SLT, SLS, etc. may be used to confirm informationindicating through which PLP a specific transport session indicated bythe SLT or SLS is transmitted may be confirmed.

In another embodiment, the PLP identifier information in theabove-described SLT, SLS, etc. will be omitted and PLP information ofthe specific transport session indicated by the SLT or SLS may beconfirmed by referring to the information in the LMT. In this case, thereceiver may combine the LMT and other IP level signaling information toidentify the PLP. Even in this embodiment, the PLP information in theSLT, SLS, etc. is not omitted and may remain in the SLT, SLS, etc.

The LMT according to the shown embodiment may include a signaling_typefield, a PLP_ID field, a num_session field and/or information on eachsession. Although the LMT of the shown embodiment describes IP streamstransmitted through one PLP, a PLP loop may be added to the LMT todescribe information on a plurality of PLPs in some embodiments. In thiscase, as described above, the LMT may describe PLPs of all IPaddresses/ports related to all service described by the SLT transmittedtogether using a PLP loop.

The signaling_type field may indicate the type of signaling informationdelivered by the table. The value of signaling_type field for the LMTmay be set to 0x01. The signaling_type field may signaling_type fieldmay be omitted. The PLP_ID field may identify a target PLP to bedescribed. When the PLP loop is used, each PLP_ID field may identifyeach target PLP. Fields from the PLP_ID field may be included in the PLPloop. Here, the below-described PLP_ID field may be an identifier of onePLP of the PLP loop and the following fields may be fields correspondingto the corresponding PLP.

The num_session field may indicate the number of higher layer sessionsdelivered through the PLP identified by the PLP_ID field. According tothe number indicated by the num_session field, information on eachsession may be included. This information may include a src_IP_addfield, a dst_IP_add field, a src_UDP_port field, a dst_UDP_port field,an SID_flag field, a compressed_flag field, an SID field, and/or acontext_id field.

The src_IP_add field, the dst_IP_add field, the src_UDP_port field, andthe dst_UDP_port field may indicate the source IP address, thedestination IP address, the source UDP port and the destination UDP portof the transport session among the higher layer sessions deliveredthrough the PLP identified by the PLP_ID field.

The SID_flag field may indicate whether the link layer packet deliveringthe transport session has an SID field in the optional header. The linklayer packet delivering the higher layer session may have an SID fieldin the optional header and the SID field value may be equal to that ofthe SID field in the LMT.

The compressed_flag field may indicate whether header compression isapplied to the data of the link layer packet delivering the transportsession. In addition, presence/absence of the below-described context_idfield may be determined according to the value of this field. Whenheader compression is applied (compressed_flag=1), the RDT may bepresent and the PLP_ID field of the RDT may have the same value as thecorresponding PLP_ID field related to the present compressed_flag field.

The SID field may indicate a sub stream ID (SID) of link layer packetsfor delivering a corresponding transfer session. The link layer packetsmay include the SID having the same value as the present SID field inthe optional header. Thereby, the receiver may filter link layer packetsusing information of the LMT and SID information of a link layer packetheader without parsing of all link layer packets.

The context_id field may provide a reference for a context id (CID) inthe RDT. The CID information of the RDT may indicate the context ID ofthe compression IP packet stream. The RDT may provide contextinformation of the compression IP packet stream. Through this field, theRDT and the LMT may be associated.

In the above-described embodiments of the signaling information/table ofthe present invention, the fields, elements or attributes may be omittedor may be replaced with other fields. In some embodiments, additionalfields, elements or attributes may be added.

In one embodiment of the present invention, service components of oneservice may be delivered through a plurality of ROUTE sessions. In thiscase, an SLS may be acquired through bootstrap information of an SLT. AnS-TSID and an MPD may be referenced through the USBD of the SLS. TheS-TSID may describe not only the ROUTE session delivered by the SLS butalso transport session description information of another ROUTE sessioncarried by the service components. To this end, the service componentsdelivered through the plurality of ROUTE sessions may all be collected.This is similarly applicable to the case in which the service componentsof one service are delivered through a plurality of MMTP sessions. Forreference, one service component may be simultaneously used by theplurality of services.

In another embodiment of the present invention, bootstrapping of an ESGservice may be performed by a broadcast or broadband network. Byacquiring the ESG over broadband, URL information of the SLT may beused. ESG information may be requested using this URL.

In another embodiment of the present invention, one service component ofone service may be delivered over the broadcast network and the otherservice component may be delivered over broadband (hybrid). The S-TSIDmay describe components delivered over the broadcast network such thatthe ROUTE client acquires desired service components. In addition, theUSBD may have base pattern information to describe which segments (whichcomponents) are delivered through which path. Accordingly, the receivercan confirm a segment to be requested from the broadband service and asegment to be detected in a broadcast stream.

In another embodiment of the present invention, scalable coding of aservice may be performed. The USBD may have all capability informationnecessary to render the service. For example, when one service isprovided in HD or UHD, the capability information of the USBD may have avalue of “HD or UHD”. The receiver may check which component isreproduced in order to render the UHD or HD service using the MPD.

In another embodiment of the present invention, through a TOI field ofthe LCT packets delivered through the LCT channel delivering the SLS,which SLS fragment is delivered using the LCT packets (USBD, S-TSID,MPD, etc.) may be identified.

In another embodiment of the present invention, app components to beused for app based enhancement/an app based service may be deliveredover the broadcast network as NRT components or may be delivered overbroadband. In addition, app signaling for app based enhancement may beperformed by an application signaling table (AST) delivered along withthe SLS. In addition, an event which is signaling for operation to beperformed by the app may be delivered in the form of an event messagetable (EMT) along with the SLS, may be signaled in the MPD or may bein-band signaled in the form of a box within DASH representation. TheAST, the EMT, etc. may be delivered over broadband. App basedenhancement, etc. may be provided using the collected app components andsuch signaling information.

In another embodiment of the present invention, a CAP message may beincluded and provided in the above-described LLS table for emergencyalert. Rich media content for emergency alert may also be provided. Richmedia may be signaled by a CAP message and, if rich media is present,the rich media may be provided as an EAS service signaled by the SLT.

In another embodiment of the present invention, linear servicecomponents may be delivered over the broadcast network according to theMMT protocol. In this case, NRT data (e.g., app components) of theservice may be delivered over the broadcast network according to theROUTE protocol. In addition, the data of the service may be deliveredover broadband. The receiver may access the MMTP session delivering theSLS using the bootstrap information of the SLT. The USBD of the SLSaccording to the MMT may reference the MP table such that the receiveracquires linear service components formatted into the MPU deliveredaccording to the MMT protocol. In addition, the USBD may furtherreference the S-TSID such that the receiver acquires NRT data deliveredaccording to the ROUTE protocol. In addition, the USBD may furtherreference the MPD to provide a reproduction description of datadelivered over broadband.

In another embodiment of the present invention, the receiver may deliverlocation URL information capable of acquiring a file content item (file,etc.) and/or a streaming component to a companion device through a websocket method. The application of the companion device may acquirecomponents, data, etc. through a request through HTTP GET using thisURL. In addition, the receiver may deliver information such as systemtime information, emergency alert information, etc. to the companiondevice.

FIG. 8 is a diagram showing a structure of a broadcast signaltransmission device of a next-generation broadcast service according toan embodiment of the present invention.

The broadcast signal transmission device of the next-generationbroadcast service according to an embodiment of the present inventionmay include an input format block 1000, a bit interleaved coding &modulation (BICM) block 1010, a frame building block 1020, an orthogonalfrequency division multiplexing (OFDM) generation block 1030, and asignaling generation block 1040. An operation of each block of thebroadcast signal transmission device will be described.

According to an embodiment of the present invention, input data may useIP stream/packet and MPEG2-TS as main input format and other streamtypes may be handled as a general stream.

The input format block 1000 may demultiplex each input stream using oneor more data pipes to which independent coding and modulation areapplied. The data pipe may be a basic unit for robustness control andmay affect quality of service (QoS). One or more services or servicecomponents may affect one data pipe. The data pipe may be a logicalchannel in a physical layer for delivering service data or metadata fordelivering one or more services or service components.

Since QoS is dependent upon the characteristics of a service provided bythe broadcast signal transmission device of the next-generationbroadcast service according to an embodiment of the present invention,data corresponding to each service needs to be processed via differentmethods.

The BICM block 1010 may include a processing block applied to a profile(or system) to which MIMO is not applied and/or a processing block of aprofile (or system) to which MIMO is applied and may include a pluralityof processing blocks for processing each data pipe.

The processing block of the BICM block to which MIMO is not applied mayinclude a data FEC encoder, a bit interleaver, a constellation mapper, asignal space diversity (SSD) encoding block, and a time interleaver. Theprocessing block of the BICM block to which MIMO is applied is differentfrom the processing block of the BICM to which MIMO is not applied inthat a cell word demultiplexer and an MIMO encoding block are furtherincluded.

The data FEC encoder may perform FEC encoding on an input BBF togenerate a FECBLOCK procedure using external coding (BCH) and internalcoding (LDPC). The external coding (BCH) may be a selective codingmethod. The bit interleaver may interleave output of the data FECencoder to achieve optimized performance using a combination of the LDPCcode and a modulation method. The constellation mapper may modulate cellword from a bit interleaver or a cell word demultiplexer using QPSK,QAM-16, irregular QAM (NUQ-64, NUQ-256, NUQ-1024), or irregularconstellation (NUC-16, NUC-64, NUC-256, NUC-1024) and provide apower-normalized constellation point. NUQ has an arbitrary type butQAM-16 and NUQ have a square shape. All of the NUQ and the NUC may beparticularly defined with respect to each code rate and signaled byparameter DP_MOD of PLS2 data. The time interleaver may be operated at adata pipe level. A parameter of the time interleaving may be differentlyset with respect to each data pipe.

The time interleaver according to the present invention may bepositioned between the BICM chain and the frame builder. In this case,the time interlever according to the present invention may selectivelyuse a convolution interleaver (CI) and a block interleaver (BI)according to a physical layer pipe (PLP) mode or may use all. The PLPaccording to an embodiment of the present invention may be a physicalpath used using the same concept as the aforementioned DP and its termmay be changed according to designer intention. The PLP mode accordingto an embodiment of the present invention may include a single PLP modeor a multiple PLP mode according to the number of PLPs processed by thebroadcast signal transmitter or the broadcast signal transmissiondevice. Time interleaving using different time interleaving methodsaccording to a PLP mode may be referred to as hybrid time interleaving.

A hybrid time interleaver may include a block interleaver (BI) and aconvolution interleaver (CI). In the case of PLP_NUM=1, the BI may notbe applied (BI off) and only the CI may be applied. In the case ofPLP_NUM>1, both the BI and the CI may be applied (BI on). The structureand operation of the CI applied in the case of PLP_NUM>1 may bedifferent from those of the CI applied in the case of PLP_NUM=1. Thehybrid time interleaver may perform an operation corresponding to areverse operation of the aforementioned hybrid time interleaver.

The cell word demultiplexer may be used to divide a single cell wordstream into a dual cell word stream for MIMO processing. The MIMOencoding block may process output of the cell word demultiplexer using aMIMO encoding method. The MIMO encoding method according to the presentinvention may be defined as full-rate spatial multiplexing (FR-SM) forproviding increase in capacity via relatively low increase in complexityat a receiver side. MIMO processing may be applied at a data pipe level.When a pair of constellation mapper outputs, NUQ e_(1,i) and e_(2,i) isinput to a MIMO encoder, a pair of MIMO encoder outputs, g1,i and g2,imay be transmitted by the same carrier k and OFDM symbol 1 of eachtransmission antenna.

The frame building block 1020 may map a data cell of an input data pipein one frame to an OFDM symbol and perform frequency interleaving forfrequency domain diversity.

According to an embodiment of the present invention, a frame may bedivided into a preamble, one or more frame signaling symbols (FSS), anda normal data symbol. The preamble may be a special symbol for providinga combination of basic transmission parameters for effectivetransmission and reception of a signal. The preamble may signal a basictransmission parameter and a transmission type of a frame. Inparticular, the preamble may indicate whether an emergency alert service(EAS) is currently provided in a current frame. The objective of the FSSmay be to transmit PLS data. For rapid synchronization and channelestimation and rapid decoding of PLS data, the FSS may have a pipepattern with higher density than a normal data symbol.

The frame building block may include a delay compensation block foradjusting timing between a data pipe and corresponding PLS data toensure co-time between a data pipe and corresponding PLS data at atransmitting side, a cell mapper for mapping a PLS, a data pipe, anauxiliary stream, a dummy stream, and so on to an active carrier of anOFDM symbol in a frame, and a frequency interleaver.

The frequency interleaver may randomly interleave a data cell receivedfrom the cell mapper to provide frequency diversity. The frequencyinterleaver may operate with respect to data corresponding to an OFDMsymbol pair including two sequential OFDM symbols or data correspondingto one OFDM symbol using different interleaving seed orders in order toacquire maximum interleaving gain in a single frame.

The OFDM generation block 1030 may modulate an OFDM carrier by the cellgenerated by the frame building block, insert a pilot, and generate atime domain signal for transmission. The corresponding block maysequentially insert guard intervals and may apply PAPR reductionprocessing to generate a last RF signal.

The signaling generation block 1040 may generate physical layersignaling information used in an operation of each functional block. Thesignaling information according to an embodiment of the presentinvention may include PLS data. The PLS may provide an element forconnecting a receiver to a physical layer data pipe. The PLS data mayinclude PLS1 data and PLS2 data.

The PLS1 data may be a first combination of PLS data transmitted to FSSin a frame with fixed size, coding, and modulation for transmittingbasic information on a system as well as a parameter required to dataPLS2 data. The PLS1 data may provide a basic transmission parameterincluding a parameter required to receive and decode PLS2 data. The PLS2data may be a second combination of PLP data transmitted to FSS fortransmitting more detailed PLS data of a data pipe and a system. PLS2signaling may further include two types of parameters of PLS2 staticdata (PLS2-STAT data) and PLS2 dynamic data (PLS2-DYN data). The PLS2static data may be PLS2 data that is static during duration of a framegroup and the PLS2 dynamic data may be PLS2 data that is dynamicallychanged every frame.

The PLS2 data may include FIC_FLAG information. A fast informationchannel (FIC) may be a dedicated channel for transmitting cross-layerinformation for enabling fast service acquisition and channel scanning.The FIC_FLAG information may indicate whether a fast information channel(FIC) is used in a current frame group via a 1-bit field. When a valueof the corresponding field is set to 1, the FIC may be provided in thecurrent frame. When a value of the corresponding field is set to 0, theFIC may not be transmitted in the current frame. The BICM block 1010 mayinclude a BICM block for protecting PLS data. The BICM block forprotecting the PLS data may include a PLS FEC encoder, a bitinterleaver, and a constellation mapper.

The PLS FEC encoder may include a scrambler for scrambling PLS1 data andPLS2 data, a BCH encoding/zero inserting block for performing externalencoding on the scrambled PLS 1 and 2 data using a BCH code shortenedfor PLS protection and inserting a zero bit after BCH encoding, a LDPCencoding block for performing encoding using an LDPC code, and an LDPCparity puncturing block. Only the PLS1 data may be permutated before anoutput bit of zero insertion is LDPC-encoded. The bit interleaver mayinterleave each of the shortened and punctured PLS1 data and PLS2 data,and the constellation mapper may map the bit-interleaved PLS1 data andPLS2 data to constellation.

A broadcast signal reception device of a next-generation broadcastservice according to an embodiment of the present invention may performa reverse operation of the broadcast signal transmission device of thenext-generation broadcast service that has been described with referenceto FIG. 8.

The broadcast signal reception device of a next-generation broadcastservice according to an embodiment of the present invention may includea synchronization & demodulation module for performing demodulationcorresponding to a reverse operation performed by the broadcast signaltransmission device, a frame parsing module for parsing an input signalframe to extract data transmitted by a service selected by a user, ademapping & decoding module for converting an input signal into bitregion data, deinterleaving bit region data as necessary, performingdemapping on mapping applied for transmission efficiency, and correctingerror that occurs in a transmission channel for decoding, an outputprocessor for performing a reverse operation of variouscompression/signal processing procedures applied by the broadcast signaltransmission device, and a signaling decoding module for acquiring andprocessing PLS information from the signal demodulated by thesynchronization & demodulation module. The frame parsing module, thedemapping & decoding module, and the output processor may perform thefunctions using the PLS data output from the signaling decoding module.

Hereinafter, the timer interleaver will be described. A timeinterleaving group according to an embodiment of the present inventionmay be directly mapped to one frame or may be spread over P_(I) frames.In addition, each time interleaving group may be divided into one ormore (N_(TI)) time interleaving blocks. Here, each time interleavingblock may correspond to one use of a time interleaver memory. A timeinterleaving block in the time interleaving group may include differentnumbers of XFECBLOCK. In general, the time interleaver may also functionas a buffer with respect to data pipe data prior to a frame generationprocedure.

The time interleaver according to an embodiment of the present inventionmay be a twisted row-column block interleaver. The twisted row-columnblock interleaver according to an embodiment of the present inventionmay write a first XFECBLOCK in a first column of the time interleavingmemory, write a second XFECBLOCK in a next column, and write theremaining XFECBLOCKs in the time interleaving block in the same manner.In an interleaving array, a cell may be read in a diagonal direction toa last row from a first row (a leftmost column as a start column is readalong a row in a right direction). In this case, to achieve singlememory deinterleaving at a receiver side irrespective of the number ofXFECBLOCK in the time interleaving block, the interleaving array for thetwisted row-column block interleaver may insert a virtual XFECBLOCK intothe time interleaving memory. In this case, to achieve single memorydeinterleaving at a receiver side, the virtual XFECBLOCK needs to beinserted into another frontmost XFECBLOCK.

FIG. 9 is a writing operation of a time interleaver according to anembodiment of the present invention.

A block shown in a left portion of the drawing shows a TI memory addressarray and a block shown in a right portion of the drawing shows awriting operation when two or one virtual FEC blocks are inserted into afrontmost group of TI groups with respect to two consecutive TI groups.

The frequency interleaver according to an embodiment of the presentinvention may include an interleaving address generator for generatingan interleaving address to be applied to data corresponding to a symbolpair.

FIG. 10 is a block diagram of an interleaving address generatorincluding a main-PRBS generator and a sub-PRBS generator according toeach FFT mode, included in the frequency interleaver, according to anembodiment of the present invention.

(a) is a block diagram of an interleaving address generator with respectto a 8K FFT mode, (b) is a block diagram of an interleaving addressgenerator with respect to a 16K FFT mode, and (c) is a block diagram ofan interleaving address generator with respect to a 32K FFT mode.

An interleaving procedure with respect to an OFDM symbol pair may useone interleaving sequence and will be described below. First, anavailable data cell (output cell from a cell mapper) to be interleavedin one OFDM symbol O_(m,l) may be defined as O_(m,l)=[x_(m,l,0), . . . ,x_(m,l,p), . . . , x_(m,l,Ndata-1)] with respect to l=0, . . . ,N_(sym)−1. In this case, x_(m,l,p) may be a p^(th) cell of a l^(th) OFDMsymbol in a m^(th) frame and N_(data) may be the number of data cells.In the case of a frame signaling symbol, N_(data)=C_(FSS), in the caseof normal data, N_(data)=C_(data), and in the case of a frame edgesymbol, N_(data)=C_(FSS). In addition, the interleaving data cell may bedefined as P_(m,l)=[v_(m,l,0), . . . , v_(m,l,Ndata-1)] with respect tol=0, . . . , N_(sym)−1.

With respect to an OFDM symbol pair, an interleaved OFDM symbol pair maybe given according to v_(m,l,Hi(p))=x_(m,l,p), p=0, . . . , N_(data)−1for a first OFDM symbol of each pair and given according tov_(m,l,p)=x_(m,l,Hi(p)), p=0, . . . , N_(data)−1 for a second OFDMsymbol of each pair. In this case, H_(l)(p) may be an interleavingaddress generated based on a cyclic shift value (symbol offset) of aPRBS generator and a sub-PRBS generator.

FIG. 11 is a diagram showing an architecture of a process of launching aCD application according to an embodiment of the present invention.

A PD refers to a primary receiver, which may be used to reproduceprimary content. A CD may communicate with the PD to provide the samecontent as the content provided by the PD or supplementary contentrelated thereto.

In some embodiments, the CD may include a laptop, a tablet, asmartphone, etc. In some embodiments, the CD may be used as a receivingdevice for displaying primary content. In some embodiments, the CD mayaccess TV related content regardless of the PD.

A method of providing a broadcast service and content related theretothrough communication between the PD and the CD may have variousembodiments.

For example, assume that a user views the concert of a favorite rock androll band thereof through a PD. Popup notification of a TV may indicatethat an alternative camera view of the concert can be viewed through aCD. Then, the user may launch an application and the application mayindicate that close-up of each musician may be provided. A viewer mayenjoy broadcast content by viewing close-up of a guitarist among guitarsolos. Main content of the TV and supplementary content of the CD may besynchronized and rendered.

In addition, for example, if a plurality of users views the TV (PD),each user may receive desired supplementary content thereof through theCD thereof User #1 may find various audio tracks through the applicationof the CD thereof and select and receive a video description for avisually impaired person through the CD thereof. User #2 may findvarious closed captions through the application of the CD thereof andselect and display an audio description for a hearing-impaired person onthe CD thereof. User #3 may convert Spanish subtitles into Englishdubbing (audio) through the application of the CD thereof and receiveEnglish dubbing through headphones connected to the CD thereof.

In addition, for example, the user may receive popup notificationindicating that the user may play along via a tablet while viewing agame show through a TV (PD). The user may launch the app of the tabletto play along with the game show in real time. Each quiz may be providedto the tablet of the user during the game show and the user may providean answer to the quiz along with the other participants of the gameshow. The score of the user may be tracked by the application andcompared with those of other viewers.

In addition, for example, when the user launches an on-demand app at thePD, this app may request information for personalization of the user andprovide program recommendation. The PD app may propose a CD app forfacilitating personalization information input and the user may inputinformation through the CD app. The user may receive a recommendedprogram through the on-demand app and select and view the programthrough the CD app. Alternatively, the recommended program may beprovided by the CD.

In addition, for example, the user may receive content provided by theTV through the CD. In this case, even when the user moves around in thehouse far away from the TV, the user may continuously view the contentthrough the CD. In addition, if an emergency alert (EA) is providedthrough a broadcast network, the user may receive an EA message or videorelated thereto through the CD even when the user is far from the TV.

In the shown architecture, the PD may include a web browser and/or a CDmanager. The web browser may execute a PD application (app). The PD appmay include HTML5 and/or web technologies related thereto. The CDmanager may be located in the PD to discover CDs, in which launchers arebeing executed, and send app launch/app installation information tothese launchers. The CD manager may also be referred to as a companionmanager.

In the shown architecture, the CD may include a launcher. The launchermay communicate with the CD manager of the PD. To this end, the launchermay launch or install a CD app. The CD app may be a web app of a webbrowser or a native app.

In order to execute the CD app, a launchCSApp (Integer enum_id, Stringpayload, function onCSLaunch) method may be used. Here, a payload of alaunchCSApp may specify an endpoint of a Websocket server. In someembodiments, this payload may also include information on a web serverendpoint. This payload may have the following format in one embodiment.

{“launch”: [

{“launchURL”:“https://www.examples-r-us.com/quiz-fallback-application.html?

colour=blue&application_uri=ws://192.168.11:992/hbbtv/”,“applicationType”: “native”},

]}

First, the CD manager may request launching of the CD app, and this maybe performed by sending an HTTP POST request to an application URL ofthe launcher of the CD. The application URL may be acquired in a devicediscovery process. BODY data of the HTTP POST request may include thepayload of the launchCSApp. This payload may indicate a CD app to beexecuted through a “launchURL” in the embodiment of the above-describedpayload. The type of the CD app to be launched may be indicated using an“applicationType” in the embodiment of the above-described payload.

FIG. 12 is a diagram showing an architecture for communication betweenan app and an app according to an embodiment of the present invention.

In the shown architecture, the PD may include a web browser, a CDmanager and/or a Websocket server.

In the present embodiment, the web browser is equal to theabove-described web browser. The CD manager may provide serviceendpoints for app-to-app communication. The Websocket server may belocated in the PD to handle Websocket connection between a PD app and aCD app.

In the shown architecture, the CD may include a launcher. The launcheris not shown. The launcher may communicate with the CD manager of thePD. To this end, the launcher may launch or install a CD app. The CD appmay be a web app of a web browser or a native app.

When the CD app is launched by the PD app, the location information of aservice endpoint may be delivered to the CD app as one of the launchparameters of a launchCSApp method. The launchCSApp is a method ofexecuting the app of the CD and a payload thereof may include thelocation information of the service endpoint. That is, in a process oflaunching the CD app, the information may be delivered to the CD. Here,the location information of the service endpoint may mean the URL of theendpoint of the Websocket server (or web server). Here, the deliveredendpoint of the Websocket server may be a remote endpoint.

FIG. 13 is a diagram showing an architecture for performingcommunication from a CD app to a PD app according to an embodiment ofthe present invention.

In the shown architecture, a PD may include a CD manager, a web serverand/or a Websocket server. The CD manager may respond to a discoveryrequest of a CD app and provide a service endpoint of a web serverand/or a Websocket server.

In the shown architecture, the web server may be located in the PD tohandle HTTP requests from the CD app and to respond to the requestsusing service and content information of the PD. The Websocket servermay be located in the PD to handle Websocket connection from the CD appand to respond to this request using service and content information ofthe PD.

In the shown architecture, the CD app may discover the PD and acquirethe service and content information from the PD through an HTTP and/orWebsocket protocol.

The CD app may establish communication with servers for providingservices in the PD. Here, the service may mean a function provided bythe web server or the Websocket server, such as ESG delivery, EAdelivery, service identification, or app-to-app communication. In orderto establish communication, the CD app may first discover the PD. Inthis process, the CD app may acquire a remote endpoint of the web serverand/or the Websocket server. The CD app may acquire service and contentinformation through the Websocket server or through an HTTP GET requestfrom the web server. If the Websocket server is used, the CD app mayfirst establish Websocket connection and request service/contentinformation through Websocket connection. If the web server is used, theCD app may issue an HTTP GET request and receive an HTTP response,thereby acquiring information.

For reference, in the architecture according to each embodiment,elements included in the PD or the CD are exemplary and may beadded/omitted/changed. In addition, in some embodiments, the PD or theCD may include all or some of the above-described elements.

A protocol for discovery will be described.

Both the PD and the CD app may transmit a multicast discovery message.This discovery message may search and/or advertise presence thereof.

On a home network, one or more PDs may be present. In addition, a CD appmay receive a discovery message from a plurality of PDs. In this case,the CD app may ask a user about with which PD the CD app is interacted.Here, information in the discovery message may be displayed to the userto assist a user's decision. Even when a plurality of CDs is present onthe home network, a reverse process may be performed.

Various mechanisms for discovery may be used. First, a scenario in whichthe CD app multicasts a search request message for PD discovery and thePD respond thereto will be described.

When the CD app is executed by the PD app, location related informationof a service endpoint provided by the PD may be delivered as theparameter of the above-described launchURL. However, in communicationfrom the CD app to the PD, the CD app needs to discover the endpointlocation of the web server or the Websocket server of the PD. That is,in this case, endpoint information (a URL, etc.) needs to be separatelyacquired.

In this case, a web server endpoint URL and a Websocket server endpointURL may be delivered to the CD app in the discovery process of the PDand the service endpoint of the PD. First, the CD app may initiatedevice discovery. This may be initiated by performing M-SEARCH using anSSDP protocol along with a search target (ST) header. For example, theM-SEARCH device discovery request may have the following format.

M-SEARCH * HTTP/1.1

HOST: 239.255.255.250:1900

MAN: “ssdp:discover”

MX: <seconds to delay response>

ST: urn:schemas-atsc.org.device: companionDevice:1.0

When the above-described device discovery request is received, the PDmay respond thereto through a LOCATION header and an ST along withHTTP/1.1 OK. For example, this response message may have the followingformat. LOCATION may include URL information for a description of adevice.

HTTP/1.1 200 OK

CACHE-CONTROL: max-age=<seconds until advertisement expires>

EXT:

LOCATION: <URL for UPnP description for root device>

SERVER: <OS/version UPnP/1.0 product/version>

ST: urn: schemas-atsc.org.device: primaryDevice:1.0

USN: <advertisement UUID>

When the above-described response message is received, the CD app mayrequest a device description file. This request is an HTTP GET requestand may be delivered to a LOCATION URL provided through the responsemessage. This request may have the following format.

GET <path component of the LOCATION URL> HTTP/1.1

Origin: http://cs.services.broadcaster.com/

When the above-described HTTP GET request is received, the PD mayrespond thereto through an HTTP/1.1 OK header including an applicationURL. This application URL may be used as a web server endpoint of thePD. This response may have the following format. In this example, theapplication URL may be represented byhttp://xx.xx.xx.xx:yyyy/applications.

HTTP/1.1 200 OK

CONTENT-LANGUAGE: <language used in description>

CONTENT-LENGTH: <bytes in body>

CONTENT-TYPE: text/xml; charset=“utf-8”

Application-URL: http://xx.xx.xx.xx:yyyy/applications

Access-Control-Allow-Origin: *

In order to discover the PD service endpoint, an HTTP GET message may bedelivered to xx.xx.xx.xx, port yyyy. This HTTP GET message may have thefollowing format.

GET/applications/ATSC HTTP/1.1

Origin: http://cs.services.broadcaster.com/4

In response thereto, the following HTTP response may be returned. Here,<X_ATSC_App2AppURL> may be used as the Websocket endpoint of the PD.

Header:

HTTP/1.1 200 OK

Origin:

Body:

<?xml version=“1.0” encoding=“UTF8”?>

<service xmlns=“urn:dialmultiscreenorg:schemas:dial” dialVer=“1.7”>

<name>ATSC</name>

<options allowStop=“false”/>

<state>running</state>

<additionalData>

<X_ATSC_App2AppURL>URL of App2App comm. endpoint </X_ATSC_App2AppURL>

<X_ATSC_UserAgent>Value of ATSC Terminal UA header</X_ATSC_UserAgent>

</additionalData>

</service>

A PD advertisement message will be described (multicast).

When the PD joins a network, the PD may multicast an SSDP message. Thismessage may serve to advertise the PD. The PD may periodically transmita multicast advertisement message. The multicast advertisement messagemay be transmitted to (239.255.255.250:1900), for example. This valuemay be changed according to embodiment. The advertisement message mayinclude PD device type information, a PD identifier, valid durationinformation, additional information related to the PD, etc. The PDmulticast advertisement message may have the following format.

NOTIFY * HTTP/1.1

HOST: 239.255.255.250:1900

CACHE-CONTROL: max-age=<advertisement validity duration in seconds>

LOCATION: <URL for primary device>

NT: urn:schemas-atsc.org:device:primaryDevice:1.0

NTS: ssdp:alive

SERVER: <Primary device ID/Version>

USN: uuid:<device uuid>:urn:schemas-atsc.org:device:primaryDevice:1.0

In the above example, information indicating that the device is“urn:schemas-atsc.org:device:primaryDevice:1.0” may be signaled in an NT(Notification Type) header (PD device type information). In addition,information indicating that the identifier of the PD is “uuid:<deviceuuid>:urn:schemas-atsc.org:device:primaryDevice:1.0” may be signaled ina USN (Unique Service Name) header (PD identifier). In addition, aduration in which this advertisement message is valid may be signaled ina CACHE-CONTROL header (valid duration information). In addition, theadditional information related to the PD may be signaled in a LOCATIONheader.

A CD advertisement message will be described (multicast). Similarly tothe above-described PD, when the CD joins the network, an SSDP messagemay be multicast. This message may be periodically transmitted and maybe transmitted to a predetermined address. The CD advertisement messagemay include CD device type information, a CD identifier, valid durationinformation and additional information related to the CD, like theabove-described PD advertisement message. The CD multicast advertisementmessage may have the following format.

NOTIFY * HTTP/1.1

HOST: 239.255.255.250:1900

CACHE-CONTROL: max-age=<advertisement validity duration in seconds>

LOCATION: <URL for companion device>

NT: urn:schemas-atsc.org:device:companionDevice:1.0

NTS: ssdp:alive

SERVER: <Companion device ID/Version>

USN: uuid:<device uuid>:urn:schemas-atsc.org:device:companionDevice:1.0

The PD multicasting a search request message for discovering the CD willbe described.

First, the PD may transmit an SSDP multicast search M-SEARCH request.This request may be transmitted to (239.255.255.250:1900), for example.This search request message may have the following format. Here, the STheader of the search request message may be set to the following CDdevice type. In addition, maximum response delay of the CD in secondsmay be indicated in an MX header.

M-SEARCH * HTTP/1.1

HOST: 239.255.255.250:1900

MAN: “ssdp:discover”

MX: <max response delay in seconds>

ST: urn:schemas-atsc.org:device:companionDevice:1.0

When the CD receives the above-described search request message from thePD, the CD may send a unicast search response message in responsethereto. This response message should be transmitted in the maximumresponse delay indicated in the MX header of the search request message.This search response message may have the following format. Here, ahuman-friendly CD device name may be provided in the format of <DevName>in the message body of the search response message.

HTTP/1.1 200 OK

CACHE-CONTROL: max-age=<advertisement validation duration in seconds>

DATE: <when response was generated>

LOCATION: <URL for device/service description for companion device>

SERVER: <Companion device ID/Version>

ST: urn:schemas-atsc.org:device:companionDevice:1.0

USN: uuid:<device uuid>:urn:schemas-atsc.org:device:companionDevice:1.0

The payload of the above-described launchCSApp method may provide aremote endpoint of the Websocket server and/or a multicast addressendpoint of a multicast group. The CD app may receive information fromthe PD app using these endpoints. In addition, app-to-app communicationmay be performed through the Websocket server.

FIG. 14 is a diagram showing a message structure for communicationbetween a CD app and a PD according to an embodiment of the presentinvention.

Communication from the CD app to the PD may be performed in thefollowing order. First, the CD app may discover the PD. In addition, theCD app may acquire web server and Websocket server endpoints of the PD.The CD app may request information through the HTTP or Websocket serviceendpoint. A request using HTTP, etc. may be transmitted to a web serverendpoint URL, etc. The PD may deliver the information to the CD appthrough an HTTP response or a Websocket service endpoint. The HTTPresponse may be a response to the HTTP request.

There may be two service endpoints. HTTP may use one service endpointfor asynchronous communication and the Websocket may use anotherendpoint for asynchronous communication. For example, communication forESG delivery and/or service information, service, show and segment datadelivery may be performed using HTTP. In addition, service and contentidentification, media playback state delivery, etc. may be performedthrough the Websocket. Communication for media timeline informationdelivery may be performed through HTTP and/or the Websocket.

First, a message structure for an HTTP request/response will bedescribed.

The CD app may send an HTTP GET request to the PD. At this time, therequest URL may have the format of<ATSCCS_PDURL>/ServiceName?<param1=val1& . . . >. An ATSCCS_PDURL is aURL acquired in a discovery process and may be a web server endpointURL. The ServiceName may indicate the name of the service related toinformation to be requested. For example, atsc3.csservice.esg.1 may be aservice name for receiving an ESG (Electronic Service Guide), andatsc3.csservices.mt.1 may be a service name for receiving media timelineinformation. If the request URL includes a web server endpoint URL and aServiceName for identifying an ESG service, this may mean that the CDapp requests ESG information delivery from the web server endpoint.

When the PD receives an HTTP GET request, the PD may transmit an HTTPresponse to the CD app. This response may include a body including anATSCCS_Message element, a ServiceName element and/or a MessageBodyelement along with an HTTP status code. The ServiceName element mayinclude the name information of the requested service and theMessageBody element may include requested information.

A message structure for the Websocket will be described.

First, the PD may receive Websocket subscription from the CD app. Whenthe received subscription is valid (does not expire or is notcancelled), the PD may transmit a Websocket message to the CD app. ThisWebsocket message may be delivered through Websocket connection andshould be delivered to the CD app whenever information of the message isupdated. This Websocket message may be referred to as a notificationmessage.

The shown embodiment (t53010) may be a subscription message transmittedby the CD app. The subscription related message between the PD and theCD may have the same format as the shown embodiment. The subscriptionmessage may include a PDCDMessageVersion element, a PDCDServiceNameelement, a PDCDMessageType element, a PDCDRespCode element and/or aPDCDSubDuration element.

The PDCDMessageVersion element may indicate the version of thesubscription message. Alternatively, this element may indicate theversion of the subscription message structure. Upper 6 bits may indicatea major version and lower 2 bits may indicate a minor version. Theversion of the subscription message structure may be 0x004, that is,version 1.0.

The PDCDServiceName element may indicate a service name related to thesubscription message. This name may uniquely identify a service betweenthe PD and the CD. For example, atsc3.services.esg.1 may indicate aservice for ESG delivery, and atsc3.services.mps.1 may indicate aservice for media playback state information delivery. A message havinga PDCDServiceName element value which does not correspond to thisservice name may be ignored.

The PDCDMessageType element may identify the type of the subscriptionmessage. The type of the subscription message is shown in an embodiment(t53020). The subscription message type may include a request messagetype and a response message type. The request message type maycorrespond to a message transmitted from the CD to the PD, and theresponse message type may correspond to a message transmitted from thePD to the CD. The request message type may include subscribe, canceland/or renew types. The message types may be message types for requestof subscription, cancellation of subscription and renewal ofsubscription. The response message type may include subscribeResponse,cancelResponse and/or renewResponse types. The message types may beresponse messages to the messages of subscribe, cancel and renew types.

The PDCDRespCode element may include a success or failure code for therequest of the message. This element may be included in the messages ofthe response message types among the above-described subscriptionrelated messages.

The PDCDSubDuration element may indicate a duration of subscription. Ifthis is included in a message transmitted from the CD to the PD, thiselement may indicate the duration of the requested subscription. If thisis included in a message transmitted from the PD to the CD, this elementmay indicate a duration in which subscription is active. This elementmay be included in all types of subscription related messages excludinga subscription cancellation message or a response message tosubscription cancellation.

The shown embodiment (t53030) may indicate the above-describednotification message or Websocket message. The notification message istransmitted from the PD to the CD, and may have the same structure asthe shown embodiment. The notification message may include aPDCDMessageVersion element, a PDCDServiceName element and/or aPDCDMessageBodyData element.

The PDCDMessageVersion element may indicate the version of thenotification message. Alternatively, this element may indicate theversion of the notification message structure. Upper 6 bits may indicatea major version and lower 2 bits may indicate a minor version. Theversion of the notification message structure may be 0x004, that is,version 1.0.

The PDCDServiceName element may indicate a service name related to thenotification message. This name may uniquely identify a service betweenthe PD and the CD. For example, atsc3.services.esg.1 may indicate aservice for ESG delivery, and atsc3.services.mt.1 may indicate a servicefor media timeline information delivery. A message having aPDCDServiceName element value which does not correspond to this servicename may be ignored.

The PDCDMessageBodyData element may include data elements specific tothe message. The syntax of this element may follow an individual messagestructure related to each PD-CD service. Such an individual message mayinclude a service/content identification message, a media timelinemessage, a media playback state message, etc. The individual messagestructure will be described below.

FIG. 15 is a diagram showing a service/content identification messageformat according to an embodiment of the present invention.

The present invention proposes a method of providing a variety of datafrom a broadcast receiver (TV receiver or PD) to a companion device (CD)in a next-generation hybrid broadcast environment using a terrestrialbroadcast network and the Internet. Here, the CD or a CD applicationlaunched in the CD may communicate with the PD.

In such data provision architecture, the PD and the CD may exchangevarious types of data. In provision of such data, the services of theabove-described Websocket endpoints, services provided by the HTTPservice URL, etc. may be used. Here, the service refers to a companionservice between the PD and the CD and is different from a broadcastservice.

For example, the PD may deliver information on a broadcast service(channel) or content (program of channel) which is currently beingprovided or will be provided by the PD to the CD. In addition, the PDmay deliver an electronic service guide (ESG) or an emergency alertmessage (EAM) to the CD. In some embodiments, the PD may deliverplayback state information of a service which is being reproduced by thePD or timeline information of the PD to the CD.

Here, the EAM is an alert message indicating emergency or accidents andmay be received by the PD and delivered to the CD. Here, the playbackstate information may mean information of a service, such as a broadcastservice which is being provided by the PD, such as playback speed, fastforward or rewind. The timeline information may include media timeinformation of a service, such as a broadcast service which is beingprovided by the PD, and/or a UTC absolute time pair.

The present invention proposes an architecture supporting communicationbetween the PD and the CD based on Websocket and supportingcommunication between the PD and the CD based on an HTTPRequest/Response. Here, a communication method according to Websocket orHTTP may be selected according to the properties of each companionservice. The present invention can implement a flexible architectureconfiguration and secure efficiency in communication between the PD andthe CD.

In one embodiment of the present invention, Websocket basedcommunication is responsible for communication for service/contentidentification and communication for playback state delivery. At thesame time, HTTP based communication performed by the web server isresponsible for communication for ESG delivery and communication forservice/show/segment related data delivery. Communication for mediatimeline information delivery may be performed by both Websocket andHTTP. In addition, in communication for service/content identification,service/content identification for a service which is currently beingbroadcast may be performed by HTTP based communication.

Communication for service/content identification will be described.Conventionally, a broadcast receiver directly provides a supplementaryservice of a broadcast service. In this case, when a user uses asupplementary service associated with a broadcast service includingcontent identification or supplementary information confirmation whileviewing a program, the broadcast program may be covered with relatedinformation. In the present invention, the related information may bedisplayed on the CD of the user, such that the user easily uses thesupplementary service using the CD capable of being easily manipulated,without interrupting viewing of the broadcast program.

In addition, in the present invention, the present invention proposes aprotocol and PD-CD architecture, a service/content identificationmessage format delivered to the CD, etc. In addition, the presentinvention proposes a method of, at a CD or a CD app, accessing aservice/content which is being provided or may be provided by the PDusing a service/content identification message. To this end, the CD mayacquire information on the broadcast service/content in advance, therebysufficiently providing supplementary service. In addition, the presentinvention proposes a method of configuring a hierarchical location URLstructure in a service/content identification message such that the CDefficiently acquires information on a service/content. In addition, thepresent invention proposes a method of using Websocket and HTTP toefficiently perform the above-described process. To this end, it ispossible to provide a supplementary service, which can be convenientlyused, without interrupting viewing of the service/content of the PD. Inaddition, the CD may acquire and reproduce the service/content oracquire and provide supplementary information related to theservice/content or perform pre-processing for efficiently performingsuch a service.

In one embodiment of the present invention, the PD may deliver aservice/content identification message to the CD or the CD app. First,in a discovery process, Websocket connection may be established. Thisprocess was described above. The Websocket server of the PD may receivea subscription message of a companion service for receiving aservice/content identification message from the CD app. The CD app maysubscribe to the companion service. This companion service may berenewed or subscription thereof may be cancelled. This companion servicemay be referred to as an ESG service.

When information related to the service/content is changed, theWebsocket server may deliver a changed service/content identificationmessage to the CD app. This service/content identification message maycorrespond to a notification message. This notification message may havea message body along with information indicating to which companionservice the message is related. In this case, the message body mayinclude information corresponding to a service/content identificationmessage. The CD app may acquire this information to perform additionallynecessary operation.

The CD app may receive a service/content identification message throughWebsocket connection and receive information on a service/contentcurrently provided by the PD using HTTP. This process may be performedby an HTTP GET message and an HTTP Response thereto. The CD app may sendan HTTP GET message to an HTTP service URL for identifying the webserver of the PD and the service/content of the web server. The webserver of the PD may send a response message to the CD app. Here, theresponse message may include information related to the service/content.

Delivery of the information related to the service/content by theWebsocket may be delivery of the information related to the wholeservice/content which is being provided or will be provided by the PD,and may correspond to delivery of synthetic information in the format ofnotification. In contrast, delivery of the information related to theservice/content by the HTTP may be delivery of information on theservice/content which is currently being provided by the PD and may beperformed by a request of the CD app.

Delivery by Websocket is delivery of synthetic full information andprovides change of an ESG, that is, update of the ESG, to the CD withouta request of the CD, thereby efficiently confirming the service/content.In this case, since a method such as a Websocket is further appropriate,the PD of the present invention supporting both the Websocket and theHTTP may use such information delivery using the Websocket. In addition,delivery by HTTP enables the CD to easily acquire related information bya request/response when the CD needs to acquire information on aservice/content which is currently being reproduced by the PD. In thiscase, since a request/response method by HTTP GET is furtherappropriate, the PD of the present invention may use an HTTP protocol.The CD may receive a service/content identification message by theWebsocket and further receive an HTTP response message to the currentservice/content.

In delivery by the Websocket, the service/content identification messagewill be described. The service/content identification message mayinclude ESG information or information obtained by processinginformation acquired from the ESG. In addition, in some embodiments, theservice/content identification message may borrow the informationstructure of the ESG.

One embodiment of the shown service/content identification message mayinclude a Service element and/or Content element. One or more Serviceelements may be included (1 . . . N), and 0 or more content elements maybe included (0 . . . N).

The Service element may describe information on a broadcast service ofthe PD. Here, the information on the service may be obtained from an ESGdata model. The Service element may include an id element, a ServiceTypeelement, a Name element, a Description element and/or aTargetUserProfile element.

The id element may indicate the identifier of the service. TheServiceType element may indicate the service type of the service. TheName element may indicate the name of the service. The Descriptionelement may include a description of the service. The TargetUserProfileelement may indicate a user profile targeted by the service.

The Content element may describe information on the content of the PD.Here, if a broadcast service is a channel, content may mean a program.The Content element may include a Programid element, a Name element, aDescription element, a TargetUserProfile element, a CARatings element, aCapabilities element, a Component element, a FileContentItem element, aTimelineInfo element and/or a Location element.

The Programid element, the Name element, the Description element and theTargetUserProfile element may include the identifier, name, descriptionand target user profile information of the content. The CARatingselement may include Content Advisory information of the content. TheCapabilities element may be capability information related to thecontent and may indicate capability information necessary tosignificantly reproduce the content.

The Component element may include information related to a componentincluded in the content. Here, the Component element may includeinformation related to continuous components of the content. Here, thecontinuous components may mean presentable components. In someembodiments, the continuous components may include audio/video/captioncomponents. In some embodiments, the continuous components may includean app based enhancement component, an app component, etc. There may bea plurality of Component elements and each Component element may furtherinclude @componentType, @componentRole, @componentName and/or@componentLocation attributes.

The @componentType attribute may indicate the type of the component. Forexample, if the attribute has values of 0, 1, 2 and 3, the component mayhave an audio component, a video component, a closed caption componentand an application component type. The remaining values may be reservedfor future use.

The @componentRole attribute may indicate the role or type of thecomponent. The @componentName attribute may indicate the name of thecomponent. Here, this name may have a human readable format. The@componentLocation attribute may include URL information for accessingthe component. Through this URL, the CD app may acquire the component.

The FileContentItem element may include information related to a filecontent item included in the content. Here, the FileContentITem elementmay include supplementary information (Adjunct Data) of the content.Here, the supplementary information may include a variety ofinformation. In some embodiments, the supplementary information mayinclude an app based enhancement component, an app component, etc. Theremay be a plurality of FileContentITem elements, which may be omitted.The FileContentITem element may include @FileContentItemLocation,@FileContentItemName, @FileContentItemID, @FileContentItemType and/or@FileContentItemEncoding attributes.

The @FileContentItemLocation attributes may include URL information foraccessing the file content item. Through this URL, the CD app mayacquire the file content item.

The @FileContentItemName attribute may indicate a human readable name ofthe file content item. The @FileContentItemID attribute may indicate theidentifier of the file content item. The @FileContentItemType attributemay indicate the type of the file content item. The@FileContentItemEncoding attribute may indicate the encoding method ofthe file content item.

The TimelineInfo element may include timeline related information of thecontent. The timeline information may be delivered by HTTP GET or aseparate Websocket service, or may be delivered in a state of beingincluded in a service/content identification message. The TimelineInfoelement may further include a currentTime element. The currentTimeelement may indicate the current time information of the content.

The Location element may include URL information for accessing thecontent. Through this URL, the CD app may acquire the content. Thiselement may be URL information for accessing the whole content unlikethe above-described URL information. In some embodiments, when a requestfor acquisition is sent using the URL information of this element, aquery term may be further attached to acquire only a necessary componentor file content item.

The service/content identification message may further include a Showelement and a Segment element. For the Show element and the Segmentelement, elements/attributes included in the above-described Serviceelement and Content element may be defined. In addition, theservice/content identification message may further include informationindicating which parts of the Service, Show, Segment and Content arecurrently reproduced by the PD based on the Service, Show, Segment andContent.

In some embodiments, the service/content identification message mayfurther include logo, other ESG information, or features (size, codec,bit rate, aspect ratio, required/desired capability) of each service,content, etc. In addition, the service/content identification messagemay further include filtering criteria information capable ofdetermining whether each service, content, etc. is suitable for aspecific personalization criterion.

In some embodiments, the URL of the above-described location informationmay be the URL of the PD (or the server of the PD) for acquiring theinformation, the URL of the Internet for direct acquisition, or the URLof an arbitrary remote server. In some embodiments, the service/contentidentification message may further include information indicatingwhether subscription is possible in order to receive each service,content, etc. and whether one-off is possible.

In delivery by HTTP, the HTTP response message for delivery of theinformation related to the current service/content will be described.

As described above, the CD app may send an HTTP GET message to an HTTPbased web server of the PD. This HTTP GET message may be requested usingservice URL information of the companion service. The HTTP GET messagemay include the service URL information and information for identifyingthe companion service (companion device for obtaining the currentservice/content related information). The HTTP GET message may furtherinclude a Query term. Through this Query term, which information isrequested may be determined.

Through the HTTP GET message, the CD app may request information on theservice/content which is currently being provided by the PD. Informationon the service content capable of being requested may include ESGinformation of the current show, currently available componentinformation, a currently available file, non-real-time data and/orcurrent timeline location information.

The PD or the web server of the PD may deliver the requested informationto the CD app through an HTTP response message. Here, the requestedinformation may be included and, if the requested information is notpresent, the information may not be included. In addition, the HTTPresponse message may further include information indicating whether theinformation is included. Here, the information delivered according tothe request may correspond to the information of the above-describedservice/content identification message. For example, the ESG informationmay correspond to id, Name, Description, CAratings elements among theabove-described Service element and sub-elements thereof and theabove-described Content element and sub-elements thereof. In addition,the component information may correspond to the above-describedComponent element and sub-elements thereof. The file or non-real-timedata information may correspond to the above-described FileContentItemelement and sub-elements thereof. In addition, the timeline locationinformation may correspond to the above-described TimelineInfo elementand sub-elements thereof.

FIG. 16 is a diagram showing a current service information messageformat according to an embodiment of the present invention.

The request for the current service information may be made according toHTTP. The CD may send an HTTP GET request to the PD to requestinformation related to the current service. Here, the current servicemay mean a service or content which is currently being provided by thePD. A request URL may be <PD Host URL>/atsc3.csservices.esg.1?<Query>.The PD Host URL may be a web server endpoint URL, andatsc3.csservices.esg.1 may be the name of a service for delivery of thecurrent service information.

The <Query> parameter may include various values to embody the HTTPrequest. The <Query> may include a ServiceInfoType parameter.

The ServiceInfoType parameter is a 32-bit field, which may indicate thetype of the currently requested service information. Service informationof the service/show/program which is currently being provided may havevarious types. For example, the current service information may includeESG information of the current show, available components of the currentshow, a current timeline location in the current show, files ornon-real-time (NRT) content of the current show, etc. One or more ofsuch information may be requested. Here, the show may mean a broadcastservice or the content, program or scene of the broadcast service.

When a ServiceInfoType[n] is an n-th bit of the ServiceInfoTypeparameter, the value of each bit may be interpreted as follows. If theServiceInfoType[0] is 1, this may indicate that the ESG information ofthe current show is requested. If the ServiceInfoType[1] is 1, this mayindicate that the available components of the current show arerequested. If the ServiceInfoType[2] is 1, this may indicate thatavailable files or NRT content of the current show are requested. If theServiceInfoType[3] is 1, this may indicate that the current timelinelocation of the current show is requested. For each bit, if the bitvalue is 0, this may indicate that the information is not requested. TheServiceInfoType[4] to ServiceInfoType[31] may be reserved for futureuse.

When a request for the current service information is received from theCD, the PD may send information on the requested type to the CD ifpossible. The PD may include the information on the requested type in anHTTP response message. In some embodiments, the PD may not includeinformation, which is not requested by the CD, in the response message.

The response message format of the current service information is shown.In some embodiments, a body part of the HTTP response may be a JSONformat and may follow a JSON schema. The HTTP response may include aServiceName element and/or a MessageBody element.

The ServiceName element may indicate the name of the PD-CD service. Inthis case, since the service is for delivery of the current serviceinformation, this element may have a value of atsc3.csservices.esg.1.

The MessageBody element may include a response message body to therequest for the current service information. The MessageBody element mayinclude a ServiceInfoRespType element, an ESGInfo element, a Componentselement, a FileContentITem element and/or a TimelineInfo element.

The ServiceInfoRespType element may be a 32-bit field, which mayindicate the type of the current service information returned as aresponse. A type such as ESG information may be indicated. When theServiceInfoRespType[n] is an n-th bit of the ServiceInfoRespTypeelement, the value of each bit may be interpreted as follows.

If the ServiceInfoRespType[0] is 1, this may indicate that the ESGinformation of the current show is included in this response message. Ifthe ServiceInfoRespType[1] is 1, this may indicate that informationrelated to the available components of the current show is included inthis response message. If the ServiceInfoRespType[2] is 1, this mayindicate that information related to the available files or NRT contentof the current show is included in this response message. If theServiceInfoRespType[3] is 1, this may indicate that information on thecurrent timeline location of the current show is included in thisresponse message. The ServiceInfoRespType[4] to theServiceInfoRespType[31] may be reserved for future use.

The ESGInfo element may be equal to the Service element of theabove-described service/content identification message and sub-elementsthereof, id, Name, Description, CARatings sub-elements of Contentelement. This element may include requested ESG information.

The Components element may be equal to the Components element of theabove-described service/content identification message and sub-elementsthereof. This element may include requested component relatedinformation.

The FileContentITem element may be equal to the FileContentItem elementof the above-described service/content identification message andsub-elements thereof. This element may include requested files or NRTcontent information.

The TimelineInfo element may be equal to the TimelineInfo element of theabove-described service/content identification message and sub-elementsthereof. This element may include requested timeline relatedinformation.

FIG. 17 is a diagram showing an ESG message format according to anembodiment of the present invention.

The request for the ESG information may be made according to HTTP. TheCD may send an HTTP GET request to the PD to request Full ESG or partialESG information. The request URL may be equal to <PD HostURL>/atsc3.csservices.esg.2?<Query>. The PD Host URL may be a web serverendpoint URL and atsc3.csservices.esg.2 may be the name of a service fordelivery of the ESG information.

A <Query> parameter may include various values to embody an HTTPrequest. The <Query> may include an ESGRequesttype parameter.

If the value of the ESGRequesttype parameter is 0, this may mean thatonly ESG information of the current show is requested. The ESGinformation of the current show may include Service, Schedule andContent fragments of the ESG of the current show. Here, the show maymean broadcast content or a program.

If the value of the ESGRequesttype parameter is 1, this may mean thatonly ESG information of the current service is requested. The ESGinformation of the current service may include Service, Schedule andContent fragments of the ESG of a current virtual channel.

If the value of the ESGRequesttype parameter is 2, this may mean thatall ESG information of all available services is requested. All ESGinformation may include Service, Schedule and Content fragments of theESG of all virtual channels, through which the ESG may be transmitted,in some embodiments.

If a request for the ESG information is received from the CD, the PD maydeliver the ESG information of the type to the CD. The PD may includethe ESG information of the requested type in an HTTP response message.The response message format of the ESG information is shown. The HTTPresponse may include an ESGResponseType element, a PDService element, aPDSchedule element and/or a PDContent element.

The ESGResponseType element may indicate the type of the requestedinformation returned as a response. If the value of this element is 0,this may indicate that only ESG information of the current show isincluded in the response message. If the value of this element is 1,this may indicate that only the ESG information of the current serviceis included in the response message. If the value of this element is 2,this may mean that the ESG information of all services is included inthe response message. This information corresponds to theabove-described ESGRequesttype parameter.

The PDService element may be a container containing a Service fragmentof the ESG information and sub-elements thereof, for the ESG typeindicated by the ESGResponseType element. The Service element of the ESGinformation may be included.

The PDSchedule element may be a container containing a Schedule fragmentof the ESG information and sub-elements thereof, for the ESG typeindicated by the ESGResponseType element. The Schedule element of theESG information may be included.

The PDContent element may be a container containing the Content elementof the ESG information and sub-elements thereof, for the ESG typeindicated by the ESGResponseType element. The Content element of the ESGinformation may be included.

In some embodiments, the PD may not deliver the ESG according to therequest. That is, if ESGRequesttype=0 or 1 or the PD cannot deliver theESG, the MessageBody element of the response may not includesub-elements. If ESGRequesttype=2, the PD preferably delivers allavailable ESGs according to the request but, in some cases, may deliveronly some ESGs along with an ESGResponseType having a lower value.

Request for and delivery of service/show/segment data will be described.

The request for the service/show/segment data may be made according toHTTP. To this end, information such as service components, file contentitems, etc. of a broadcast service or content may be delivered to theCD.

Continuous or presentable components may be accessed through the URL ofthe ComponentLocation element of the above-described service/contentidentification message. The CD app may make an HTTP GET request throughthis URL to acquire the component or component related information.

Adjunct data, that is, file or data components may be accessed throughthe URL of the FileContentItemLocation element of the above-describedservice/content identification message. The CD app may make an HTTP GETrequest using this URL to acquire files, data, etc.

In some embodiments, such a request may be made through the URLindicated by the Location element indicated by the above-describedservice/content identification message.

Request for and delivery of media timeline information will bedescribed.

Request for the media timeline information may be made through HTTPand/or Websocket. The response message of the HTTP or the notificationmessage of the Websocket may include absoluteTime information and/ormediaTime information. The absoluteTime information may mean current UTCtime information, and the mediaTime information may indicate the mediatime at the current UTC time. By sending such two pieces of information,the CD may acquire the media timeline related information.

FIG. 18 is a diagram showing a media playback state message formataccording to an embodiment of the present invention.

The media playback state related information may be delivered to the CDthrough Websocket connection. The shown message body format may beincluded in the message body part of the notification message of theWebsocket to be delivered from the PD to the CD.

The media playback state related information may include an MPStateelement, an MPSpeed element and/or a MediaID element.

The MPState element may indicate the current playback state of themedia. Here, the media may be a media identified by the below-describedMediaID element or a media which is currently being provided by the PD.The value of this element may be one of “PLAYING”, “PAUSED”, “STOPPED”,“BUFFERING” and “UNKNOWN”. The “STOPPED” state may mean the end of themedia stream.

The MPSpeed element may indicate the current playback speed of the mediarelative to a normal speed. If the value of this element is a positivevalue, this may mean forward playback. Forward playback may mean that amedia timeline position increases as a wall-clock time increases. If thevalue of this element is a negative value, this may mean backwardplayback. Backward playback may mean that a media timeline positiondecreases as a wall-clock time decreases.

If the value of this element is 1, this may mean that the media isplayed back forward at a normal speed. In the case of forward playbackat the normal speed, the media timeline may increase by the same amountas increase in the wall-clock time. If the value of this element is −1,this may mean that the media is played back backward at the normalspeed. In the case of backward playback at the normal speed, the mediatimeline may decrease by the same amount as decrease in the wall-clocktime.

If the value of this element is X and X is not 0 or 1, this may meanthat the media is played back at a speed which is X times the normalspeed. In this case, the media timeline may increase by X times thewall-clock time (if X is a positive value) or decrease by X times thewall-clock time (if X is a negative value).

If the value of this element is 0 and the current MPState is “PLAYING”,this may mean an UNKNOWN playback speed. If the MPState is any stateexcluding “PLAYING”, the value of this element may be 0.

In addition, if the MPState is “PLAYING” and this element is notpresent, this element may be inferred to have a value of 1. In addition,if the MPState is any state excluding “PLAYING” and this element is notpresent, this element is inferred to have a value of 0. This element maybe included in the response message if the PD supports a PVR function.

The MediaID element is the identifier of the media, which may identify atarget media, the media playback state information of which isrequested. This identifier may uniquely identify the media in the PD,from which the media playback state information is requested. If thiselement has a value of “CURRENT”, this may mean that information on mainmedia currently played back by the PD is requested.

In some embodiments, one or more {MPState, MPSpeed, MediaID} sets may beincluded in the MessageBody.

FIG. 19 is a diagram showing an EA message according to an embodiment ofthe present invention.

An EAM (EA Message) may be received by the PD and may be rendered by acontrol function of the PD. The EAM may be received through a broadcastnetwork or broadband. The received EAM may be delivered to the CDthrough a local area network. This delivery process may include aprocess of, at the PD app of the PD, launching the CD app at the CD anddelivering an EAM to the CD app(s) for rendering.

The EAM may be delivered to the CD in a Websocket and/or multicastmanner. In a scenario for EAM delivery, the PD may include a PD app, aCD manager, a Websocket server and/or a multicast sender.

The PD app may be responsible for delivering the EAM to available CD(s)in a local area network. The CD manager is equal to the above-describedCD manager and may be responsible for discovering a CD in which alauncher is being executed and delivering execution information forlaunching an EA CD app (emergency CD application) to the launcher.

The Websocket server may be equal to the above-described Websocketserver and handle Websocket communication (connection) between the PDapp and the launched EA CD app. The multicast sender may be responsiblefor transmitting a multicast message from the PD app within the PD.

In this scenario, the CD may include a launcher and/or an EA CD app. Thelauncher is equal to the above-described launcher and may be responsiblefor communicating with the CD manager of the PD and launching the EA CDapp of the CD. The EA CD app may be a CD app for receiving the EAM fromthe PD and displaying the EAM to the user.

While executing the internal control function, the PD may receive theEAM. In response thereto, the internal control function may launch anembedded PD app. The PD app may render this EA and may manage theprocess of rendering the EA at the CD(s) in the local network.

First, the process of delivering the EAM from the PD app to the EA CDapp through the Websocket will be described.

The PD app may find all CDs available in the launcher through adiscoverCSLauncher( ) method, in order to launch the CD app to receiveand render the EAM. If a CD having a launcher is not found, the PD appmay end. If a CD having a launcher is found, the PD app may find a localendpoint of a PD Websocket communication service through agetApp2AppLocalBaseURL( )method. In addition, the PD app may find aremote endpoint of a PD Websocket communication service through agetApp2AppRemoteBaseURL( )method. Here, the endpoint of the Websocketcommunication service may mean endpoints of the Websocket server.

For each found CD, the PD app may launch the EA CD app through alaunchCSApp( )method. Before launching, the EA CD app to be launched maybe identified through a LaunchURL. In addition, the remote endpoint ofthe Websocket communication service may also be identified. Eachlaunched EA CD app may access the URL of the remote endpoint of the PDWebsocket communication service. The EA CD app to be launched may beidentified and launched through a LaunchURL. In the process of launchingthe EA CD app, remote endpoint information may be delivered to the CD.

The PD app may be attached to the local endpoint of the Websocketcommunication service, and the EA CD app may be attached to the remoteendpoint. To this end, Websocket connection between the PD app and theEA app may be established. If connection is established, the PD app maydeliver the received EAM to the EA CD app. The EA CD app may process andrender the EAM.

The process of delivering the EAM from the PD app to the EA CD app in amulticast manner will be described.

The PD app may find all CDs available in the launcher through adiscoverCSLauncher( )method. For each found CD, the PD app may executethe EA CD app through a launchCSApp( )method. In this process, EA CD apprelated information identified by LaunchURL and/or multicast informationmay be delivered to the CD. The multicast information may include amulticast group address and/or multicast port information. According tocontext, the multicast group address and the multicast port informationmay be collectively referred to as a multicast group address. Eachlaunched EA CD app may access the multicast group address.

The launched EA CD app may check whether the EA CD app has multicastgroup information for EA. If the EA CD app does not have suchinformation, the EA CD app may send a request to a known endpoint of thePD. The PD may send the above-described multicast information as aresponse. If the EA CD app has multicast information, the EA CD app mayjoin the multicast group for EA. In this process, the multicast groupaddress may be used.

After the EA CD app is launched, the PD app may transmit the EAM to themulticast group address using the multicast sender. To this end, the EAMmay be delivered to the EA CD app. The EA CD app may receive the EAM andprocess and render the EAM.

If the EAM rendering time expires, the PD app may send a terminationrequest to the multicast group address to terminate all EA CD apps.Thereafter, the PD app may end.

The format of the EAM will be described. One embodiment of the EAM isshown.

As described above, as soon as the EAM is received by the PD, the EAMmay be delivered to the CD. In this process, a subscription ID, initialcontent of the EAM, characteristic information of the initial content ofthe EAM, additional content, etc. may be delivered to the CD along withthe EAM. Here, the characteristics of the initial content of the EAM maymean a new message, a continuous message and/or a one-time message ormay mean whether a rich media is included in addition to text.

In the shown embodiment, a plurality of EAMs may be delivered to the CDat a time in some embodiments. That is, the EAMNotification element mayinclude a plurality of EAM elements.

The EAM element may include an EAMID attribute, a SentTimestampattribute, an ExpiredTimestamp attribute, a Category attribute, anUrgency attribute, a Severity attribute, a Geo-loc attribute, a NewMsgattribute, a OneTimeMsg attribute, an EAMContent element, an Add1EAMURLelement, an EAMContentAccessibilityURL element, an Add1EAMPhone elementand/or a ContactEmail element.

The EAMID attribute may indicate the identifier of the EA message (EAM).This identifier may uniquely identify the EA message.

The SentTimestamp attribute may indicate the date and/or time when theEA message is generated. For example, the SentTimestamp attribute mayindicate a first moment when the EA message becomes valid.

The ExpiredTimestamp attribute may indicate a last moment (date and/ortime) when the EA message becomes valid.

The Category attribute may indicate the category of the EA message. Forexample, the Category attribute may indicate at least one of Geo, Met,Safety, Rescue, Fire, Health, Env, Transport, Infra, and/or CBRNE.

The Urgency attribute may indicate urgency of the EA message. Forexample, the Urgency attribute may indicate at least one of Immediate,Expected, Future, and/or Past.

The Severity attribute may indicate the severity of the EA message. Forexample, the Severity attribute may include at least one of Extreme,Severe, Moderate, and/or Minor.

The Geo-loc attribute may indicate a geographical location, to which theEA message is applicable.

The NewMsg attribute may indicate whether the EA message is a newmessage. If the value of the NewMsg attribute is “true”, this EA messagemay be a new message. If the value of the NewMsg attribute is “false”,this EA message may be repetition of a previous EA message.

The OneTimeMsg attribute may indicate whether the EA message istransmitted only once. If the value of the OneTimeMsg attribute is“true”, this EA message may be transmitted only once and may not berepeatedly transmitted. If the value of the OneTimeMsg attribute is“false”, this EA message may be repeated at least once.

The EAMContent element may include the message content of the EAmessage. The EAMContent element may further include a ContentFormatattribute. The ContentFormat attribute may indicate the type of thecontent of the EA message included in the EAMContent element.

The Add1EAMURL element may indicate a URL for providing additionalinformation of the EA message. This URL may provide more informationthan information included in the EAMContent element. To this end,additional content, etc. for emergency alert may be acquired.

The EAMContentAccessibilityURL element may indicate a URL for providinginitial emergency alert (EA) message content for accessibility. This maybe a URL for acquiring information for fast alert in addition to maincontent for EA. In some embodiments, this element may indicate a URL forproviding the EA and a secondary audio stream for facilitatinginformation provision according to EA. This may be performed accordingto a requested method based on the FCC rule.

The Add1EAMPhone element may indicate a phone number for obtaining moreinformation of the EA message. The ContactEmail element may indicate anemail address for providing more information of the EA message.

In some embodiments, the EAMNotification element may further include aSubscriptionID element, a PDDevID element and/or a PDVersion element.

The SubscriptionID element may indicate a subscription identifier forsubscription of the EA message. The SubscriptionID element may be usedto uniquely identify subscription from the CD to the PD. The PDDevIDelement may be the device identifier of the PD. The PDVersion elementmay indicate the version information of the PD.

The EAM may follow an XML format or a JSON format. The EAM may bechanged to an XML format, and the changed XML schema may be definedaccording to the standard XML convention based on the above-describedelements/attributes.

In some embodiments, the PD app and the CD app may operate in tandem. Inthis case, communication between the PD app and the CD app may beperformed, and a protocol such as Websocket may be used therein. Adiscovery process may use DIAL, SSDP, UPnP, etc. in addition to theabove-described method.

FIG. 20 is a diagram showing a subscription related message and anotification message of a Websocket protocol in JSON schema according toan embodiment of the present invention.

In PD-CD communication according to the Websocket protocol, asubscription related message from the PD to the CD or from the CD to thePD is shown (t59010). The shown format may be represented in JSON formator XML format in some embodiments.

In addition, in PD-CD communication according to the Websocket protocol,a notification message from the PD to the CD is shown (t59020). Theshown format may be presented in JSON format or XML format in someembodiments.

FIG. 21 is a diagram showing delivery of electronic service guide (ESG)information through a broadcast network according to an embodiment ofthe present invention.

The ESG may provide a service guide for a broadcast service andbroadcast content of the service. ESG information may be divided intovarious fragments and such ESG information may be encapsulated anddelivered to a broadcast receiver, etc. The ESG may include a servicefragment, a schedule fragment, a content fragment, etc.

The service fragment may describe content items included in onebroadcast service at an aggregate level. That is, the service fragmentmay provide service guide information of the broadcast service. Here,the content item may mean a component, data, signaling information, etc.included in the service.

The service fragment may include ID information of the service, typeinformation of the service, service name information, descriptioninformation of the service, audio language or text language informationof the service, advisory rating information of the service, genreinformation, broadcast area information, etc. In addition, the servicefragment may include ID information of the service fragment, versioninformation and valid period information of the service fragment. Inaddition, the service fragment may include an extension elementincluding a major/minor channel number, icon information, etc. of theservice.

The broadcast service may be delivered to users using a plurality ofaccess methods. (e.g., a broadcast network or an interactive (Internetor broadband) channel). In addition, the broadcast service may target aspecific user group or a specific geographical area. According to type,the service may have an interactive part and/or a broadcast-only part.

In some embodiments, there is no component which is not related to anybroadcast content and is related to the function (e.g., purchase,subscription, etc.) of the service. As a part of the service guide, theservice fragment may form a central hub referenced by other fragmentsincluding the schedule fragment and/or the content fragment.

Along with the fragments of the related ESG, a terminal (broadcastreceiver, etc.) may check details related to the broadcast serviceanytime. Such details may summarize and indicate when and how relatedcontent is consumed on a user-friendly display.

The schedule fragment may define time frames capable of streaming,downloading and/or rendering related content items. That is, theschedule fragment may provide information indicating an available timeinterval of a service, content, etc.

The schedule fragment may include the ID, version, and valid periodinformation of the schedule fragment. In addition, the schedule fragmentmay include service reference information for referencing a relatedservice fragment and/or content reference information for referencing arelated content fragment. Each of the service reference informationand/or the content reference information includes ID referenceinformation and the service fragment and the content fragment may bereferenced using these IDs.

In some embodiments, the schedule fragment may reference one or moreservice fragments. If at least one content fragment is referenced, theschedule fragment may define valid distribution of the content itemsincluded in the service and/or a presentation time frame. That is, insome embodiments, the above-described content reference information mayinclude presentation window information. The presentation windowinformation may indicate a time interval when the referenced content maybe rendered. The presentation window information may include a starttime, an end time, a duration, ID information, etc. If the schedulefragment does not reference the content fragment, the schedule fragmentmay define a time frame capable of using the service.

The content fragment may provide a detailed description of a specificcontent item or a specific content. That is, the content fragment mayprovide service guide information of any content. The content fragmentmay include ID information of the content, name information of thecontent, description information of the content, audio language or textlanguage information of the content, advisory rating information of thecontent, genre information, service reference information of the servicefragment related to the content or target user profile information. Inaddition, the content fragment may include ID information of the contentfragment, version information, valid period information (validFrom,validTo) of the content fragment, etc.

In addition, the content fragment may include an extension element,which may include information on components included in the content. Inaddition, in some embodiments, this element may include information onfile content items related to the content. Information on this componentor file content items may include the type, role, description, ID, nameor encoding method of the component or the file content items.

As described above, the content fragment may provide not only the type,description, and language information of the content but also targetuser group information, target geographical area information, advisoryrating information, etc. The content fragment may be referenced by theschedule fragment and the service fragment related to the content may bereferenced.

The SGDD (Service Guide Delivery Descriptor) may be transmitted througha service guide announcement channel. The SGDD may notify a terminal ofinformation such as availability of data, metadata, grouping of serviceguide fragments, etc. in a service guide discovery process. The SGDD mayenable fast identification of service guide fragments. Here, the serviceguide fragments may be cached in a terminal or transmitted to theterminal. Therefore, the SGDD may be repeatedly transmitted if the SGDDis distributed through a broadcast channel. The SGDD may providegrouping of related service guide fragments to determine whether thegroup becomes perfect.

The SGDD may be used when the terminal is moved from one servicecoverage area to another area. In this case, the SGDD may be used tocheck which of the service guide fragments received in a previous areais valid even in a current area. The valid service guide fragments maynot be parsed or processed again.

ESG delivery will be described.

ESG delivery may be performed through a broadcast network or broadbandas described above. Such ESG delivery may be performed in a service datadelivery structure using the above-described ROUTE/MMT.

Each delivery method has unique characteristics but may share a datastructure used to manage organization of ESG fragments in a transportlayer. This data structure may be the above-described SGDD and/or SGDU(Service Guide Delivery Unit). The above-described service guidefragments may be encapsulated into SGDUs. The SGDUs may be described bySGDDs.

The SGDU may be a transmission container for delivering theabove-described service guide fragments. A broadcast system andreceivers for the broadcast system may support processing of the SGDUstructure. Here, the SGDU may include a unit header and/or a unitpayload.

The unit header may include an extension_offset field and/or ann_o_service_guide_fragments field.

The extension_offset field may indicate an offset from a start point ofthe unit payload to a start point of a first extension. In the case ofthe SGDU according to the present invention, the value of this field maybe 0. The receiver according to the present invention should process anSGDU having a non-zero value. If the SGDU having a non-zero value isreceived, processing may be performed by ignoring the extension.

The n_o_service_guide_fragments field may indicate the number of serviceguide fragments encapsulated in the SGDU.

The unit payload may include a fragmentEncoding[i] field and/or afragmentType[i] field.

The fragmentEncoding[i] field may be a field for signaling encoding ofan i-th service guide fragment. There are various encoding methods.However, in the SGDU according to the present invention, at least oneservice guide fragment encoded in XML may be included. The receiveraccording to the present invention may ignore fragment data having aservice guide fragment encoded in XML in the SGDU.

The fragmentType[i] field may be a field for signaling the type of ani-th service guide fragment. For the service guide fragment encoded inXML, the fragment type may be one of a service fragment, a contentfragment or a schedule fragment. The SGDU according to the presentinvention may include at least one service guide fragment correspondingto these three fragment types. The receiver according to the presentinvention may ignore service guide fragment data having a type otherthan the service guide fragment corresponding to these three fragmenttypes.

The SGDU is a structure used to encapsulate fragment subsets for thetransport layer, and may be used regardless of the transport method(transport independent). In contrast, the SGDD may be partially relatedto the transport method (partially transport dependent). The SGDD maydescribe how each service guide fragment is available in a transportlayer while describing service level information of the ESG. That is, insome embodiments, the SGDD may describe information indicating howrelated ESG data is acquired over a broadcast network or broadband.

If the ESG is delivered over a broadcast network, ESG information may bedelivered in the format of an ESG service. That is, the ESG informationmay be defined and delivered as an ESG service. As described above, theESG service may be defined in the service category.

In this case, an SLT may indicate that, for the ESG service, deliverythrough a broadcast network of an SLS is performed through a ROUTEsession. This ROUTE session may transmit an SGDD and, in someembodiments, transmit an SGDU related to the ESG. In some embodiments,these may be delivered in the form of an MME message. In someembodiments, the terminal may poll fragments.

If the ESG is delivered through broadband, the ESG information mayacquire a signaling URL for an ESG server provided by the SLT. SignalingURL information in the SLT was described above. Through this URL, theterminal may request all or some of the ESG fragments from the server.

Delivery mechanism through a broadcast network and broadband may deliveran SGDD (and/or SGDU) for the service guide alone. That is, a deliverysession for another service guide may not deliver an SGDD and an SGDUfor the service guide.

An ESG information delivery diagram through the broadcast network willbe described.

First, in the shown SLT, a service identified by service_id=0x1011 maybe a general broadcast service. This broadcast service may be a generalbroadcast service classified into a linear service by service categoryinformation on the SLT. The SLS of this service may be transmittedthrough a ROUTE session identified by sIP1, dIP1 and dPort1 as providedby the SLT. Specifically, this SLS may be delivered through a predefinedLCT channel of the ROUTE session (LCT channel identified by the showntsi-sls). This SLS may include information such as USBD/USD, S-TSID andMPD as described above. The session information of the S-TSID may beacquired by video/audio components for the broadcast service. In theshown embodiment, audio segments may be delivered throughPLP#1-ROUTE#1-LCT(tsi-a), and video segments may be delivered throughPLP#2-ROUTE#1-LCT(tsi-v).

In addition, in the shown SLT, the service identified byservice_id=0x1055 may be the above-described ESG service. The servicecategory information on the SLT may also indicate that the service is anESG service. The transport path of the SLS for this ESG service may beprovided by the SLT using the same method. This SLS may be transmittedthrough a ROUTE session identified by sIP2, dIP2 and dPort2. This SLSmay be delivered through a predefined LCT channel in the ROUTE session(LCT channel identified by the shown tsi-sls). This SLS may include aUSBD/USD and/or an S-TSID. The USBD/USD may include information forreferencing an S-TSID.

This S-TSID may indicate an LCT channel, through which the SGDD of theESG service is delivered and/or an LCT channel, through which the SGDUis delivered. This may be indicated by tsi information in the S-TSID.The SGDD may be delivered through an LCT channel identified by tsi-e.FDT information may be delivered through a transport object identifiedby toi-0 of the LCT channel, and the transport object, through which theSGDD is delivered, may be identified by this FDT information. Inaddition, SGDUs may be delivered through an LCT channel identified bytsi-eu. FDT information may be delivered through a transport objectidentified by toi-0 of the LCT channel and the transport objects,through which the SGDUs are delivered, may be identified by this FDTinformation. In the shown embodiment, each SGDU may include a servicefragment, a schedule fragment and/or a content fragment.

Like the above embodiment, one LCT channel of one ROUTE session may beused to deliver SGDDs. This LCT channel may be referred to as a serviceguide announcement channel. One or more different LCT channels of theROUTE session may be used to deliver SGDUs.

The ESG service may be provided through a broadcast network according tothe above-described method. In the above-described embodiment, TSIvalues are exemplary and the actual values of the TSI may be different.

FIG. 22 is a diagram showing transport related information included inan SGDD according to an embodiment of the present invention.

This transport related information may indicate in which path ESG datais delivered in a service data delivery structure using theabove-described ROUTE/MMT.

The SGDD may further include a Transport element. This element mayinclude shown transport related information. As described above, the ESGservice may be delivered through a ROUTE protocol.

The structure of the Transport element is shown. The Transport elementmay indicate a transport session for delivering service guide fragmentsdelivered in the SGDUs corresponding to this element. The Transportelement may include an ipAddress attribute, a port attribute, asrcIpAddress attribute, a transmissionSessionID attribute and/or ahasFDT attribute.

The ipAddress attribute may indicate the destination IP address of theROUTE session for delivering the SGDU.

The port attribute may indicate the destination port number of the ROUTEsession.

The srcIpAddress attribute may indicate the source IP address of theROUTE session. If a source-specific multicast scheme is applied totransmission, this attribute may have, as a value thereof, an IP addresscapable of being found from IP packets included in the IP stream. Ifthis attribute is omitted, there may be one source IP address, fromwhich a file delivery session defined by a given destination IP address,port and transmission session is derived.

The transmissionSessionID attribute may indicate TSI (TransmissionSession Identifier) information which may be used at the LCT level. ThisTSI value may identify an LCT channel, through which the SGDU related tothe ESG is delivered.

The hasFDT attribute may indicate whether the FDT is transmitted throughthe corresponding transmission session. That is, if the FDT is deliveredthrough the transmission session in which service guide fragments aredelivered, this attribute may have a “true” value. Otherwise, thisattribute may have a “false” value. The default value of this attributemay be “true”. If this attribute has a “false” value, FEC parametersrelated to the transport object for delivering SGDUs in thecorresponding transmission session may be signaled by EXT_FTI of RFC3926. In addition, information on optional compression of SGDUs may besignaled using EXT_CENC of RFC 3926. The EXT_CENC may be generallydefined to signal encoding of the FDT but may be defined to be used foranother purpose for a specific SGDU delivery scheme using ALC.

FIG. 23 is a diagram showing a service/content identification messageformat according to another embodiment of the present invention.

As described above, a service/content identification message may bedelivered through the Websocket. The service/content identificationmessage may be used for the above-described communication forservice/content identification.

In the service/content identification message according to the shownembodiment, a CARatings element and/or a TimelineInfo element areomitted. In addition, FileContentItem elements are not distinguishedfrom Component elements and thus are handled as Component elements. Inaddition, the internal information of the Component element was omitted.In some embodiments, the structure of the service/content identificationmessage and/or the internal information may be added/changed/deleted.

The service/content identification message according to theabove-described embodiment and the shown embodiment may be generatedbased on the information on the above-described ESG. That is, the PD mayreceive the ESG using a reception component through a broadcast networkor broadband. When a new ESG is received, the PD may deliver theservice/content identification message to the CD apps subscribing tocommunication for service/content identification. The PD may generate aservice/content identification message, for communication forservice/content identification. At this time, the service/contentidentification message may include information extracted from the ESG.In some embodiments, the PD may further include supplementaryinformation in the service/content identification message, withoutincluding the information extracted from the ESG. To this end, theservice/content identification message may be generated.

In the service/content identification message according to theabove-described embodiment and the shown embodiment, the service elementmay include all or some of the information in the service fragment ofthe above-described ESG. In some embodiments, the service element mayinclude the service ID information, the service type information, theservice name information, the service description information and/or thetarget user profile information of the service among the servicefragment information of the ESG. These may correspond to the id element,the ServiceType element, the Name element, the Description elementand/or the TargetUserProfile element in the above-described serviceelement. That is, in the process of generating the service/contentidentification message, the above-listed information of the servicefragments of the ESG may be selected and included in the service/contentidentification message.

In the service/content identification message according to theabove-described embodiment and the shown embodiment, the content elementmay include all or some of the information in the content fragments ofthe above-described ESG. In some embodiments, the content element mayinclude ID information of the content, name information of the content,description information of the content, rating information of thecontent, and/or capability information of the content. These maycorrespond to a Programid element, a Name element, a Descriptionelement, a TargetUserProfile element, a CARatings element and/or aCapabilities element in the above-described content element.

In addition, as described above, the content fragment of the ESG mayinclude an extension element, and the extension element may include acomponent included in the content and/or information related to a filecontent item. This information may also be acquired from the ESG to beincluded in the service/content identification message. Information inthe above-described Component element and/or FileContentItem element maybe acquired from the information in the ESG. Information such as an ID,type, role, name, etc. of each component and/or file content item may beincluded in @componentID, @componentType, @componentRole, @componentNameor @FileContentItemID, @FileContentItemType, @FileContentItemEncoding,@FileContentItemName, etc.

That is, in the process of generating the service/content identificationmessage, the above-listed information of the content fragments of theESG may be selected and included in the service/content identificationmessage.

In addition, in addition to the information acquired from the receivedESG, other information may be included in the service/contentidentification message. The above-described @componentLocationinformation may be included in the Component element. In addition, theabove-described @FileContentItemLocation information may be included inthe FileContentItem element. In addition, the above-described Locationelement may be included in the Content element. Each piece of locationinformation may be equal to the above-described location information.

Such location information and URL information included therein may beused for communication for the above-described service/show/segmentrelated data delivery.

In addition, timeline related information of content may be additionallyincluded in the service/content identification message. This timelineinformation may not be acquired from the ESG. This timeline informationmay correspond to the above-described TimelineInfo element and may beequal to the above-described timeline information.

Although not shown, filtering criteria information of theservice/content may be included in the service/content identificationmessage. The filtering criteria may be criteria used for personalizationor parental control.

In communication for the above-described current service informationdelivery, the above-described current service information message mayinclude an ESGInfo element, a Components element, a FileContentItemelement and/or a TimelineInfo element. At this time, the above-listedelements included and delivered in the current service informationmessage may include information corresponding to the elements of theabove-described service/content identification message.

That is, the ESGInfo element requested by setting ServiceInfoType [0] to1 may include the service element of the service/content identificationmessage and sub-elements thereof. In addition, the ESGInfo element mayinclude id, Name, Description, and CARatings sub-elements of the Contentelement of the service/content identification message.

The Components element requested by setting ServiceInfoType [1] to 1 mayinclude the Component element of the service/content identificationmessage and sub-elements thereof.

The FileContentItem element requested by setting ServiceInfoType [2] to1 may include the FileContentItem element of the service/contentidentification message and sub-elements thereof.

The TimelineInfo element requested by setting ServiceInfoType [3] to 1may include the TimelineInfo element of the service/contentidentification message and sub-elements thereof.

In acquisition of information related to the ESG or the service/content,as described above, there is a method of using communication forservice/content identification or a method of using communication forcurrent service information delivery.

When the ESG information is received, the PD may notify the CD apps ofthe service/content identification message using Websocket connection,thereby delivering the information to the CD. In addition, the CD mayacquire necessary information through an HTTP request and response, ifnecessary. By defining an information delivery method using such twoprotocols, information delivery between the PD and the CD may beefficiently performed. In particular, although subscription of the CDapp is performed after a notification time through Websocket connection,necessary information may be delivered.

FIG. 24 is a diagram showing ESGRequesttype parameters which may be usedfor communication for ESG delivery according to another embodiment ofthe present invention.

The above-described ESG message format (t24010) may include a PDServiceelement, a PDSchedule element and/or a PDContent element. These elementsmay correspond to the service fragment, schedule fragment and contentfragment of the above-described ESG. That is, the fragment informationof the related ESG may be included in each ESG message format to bedelivered to the CD.

In addition, in communication for the above-described ESG delivery, ESGinformation may be requested from the PD and delivered to the CDaccording to the ESGRequesttype parameter value. In the above-describedembodiment, the ESGRequesttype parameter value is 0, 1 and 2.

The shown embodiment (t24020) may be an extension of the above-describedESGRequesttype parameter. The ESGRequesttype parameter values of 0, 1and 2 are equal to those of the above-described embodiment.

If the ESGRequesttype parameter value is 3, this may mean that onlyfiltered ESG information of the ESG information of the current show isrequested. Here, the filtered ESG information may mean ESG informationfiltered according to device capability and/or parental control settingof the PD in the ESG information received by the PD. In someembodiments, the filtered ESG information may mean ESG informationfiltered according to device capability and/or parental control settingof the CD in the ESG information received by the PD. The filtered ESGinformation may be delivered to the CD, thereby preventing unnecessaryinformation from being delivered to the CD. The ESG information of thecurrent show may include the Service, Schedule, and Content fragments ofthe ESG of the current show. Here, the show may mean broadcast content,a program, etc.

If the ESGRequesttype parameter value is 4, this may mean that onlyfiltered ESG information of the ESG information of the current serviceis requested. The meaning of the filtered ESG information may be equalto that of the above-described filtered ESG information. The ESGinformation of the current service may include the Service, Schedule,and Content fragments of the ESG of the current virtual channel.

If the ESGRequesttype parameter value is 5, this may mean that onlyfiltered ESG information of all the ESG information of all availableservices is requested. The meaning of the filtered ESG information maybe equal to that of the above-described filtered ESG information. Allthe ESG information may include the Service, Schedule, and Contentfragments of the ESGs of all virtual channels, through which the ESG maybe transmitted, in some embodiments.

In some embodiments, the ESGRequesttype parameter values of 3, 4 and 5may not be defined. In addition, in some embodiments, the ESGRequesttypeparameter values of 0, 1 and 2 may not be defined.

In addition to communication for service/content identification andcommunication for current service information delivery, communicationfor ESG delivery is defined. Using communication for ESG delivery, theCD app may acquire ESG information according to situation. ESG relatedinformation may be delivered through various protocols, therebygenerally using data in various CD apps and selecting an efficientdelivery method according to situation.

Communication according to Websocket notifies the CD apps of informationand may be referred to as a notification service. For example, forcommunication for service/content identification, the CD app maysubscribe to a service/content identification notification service andthe PD may deliver the service/content identification message to a CDapp having valid subscription.

FIG. 25 is a diagram showing a method of processing a broadcast serviceat a PD according to an embodiment of the present invention.

The method of processing the broadcast service at the PD according tothe embodiment of the present invention may include performing adiscovery process with a CD app, establishing Websocket connection,receiving a subscription message for subscription to a serviceidentification notification service, receiving an electronic serviceguide (ESG), generating a service identification message and/ordelivering a service identification message to the CD app subscribing tothe service identification notification service through Websocketconnection.

First, the companion manager of a broadcast reception device operatingas the PD may perform the discovery process with the CD app(application) which is being launched in a companion device (CD). Inthis process, endpoint information of a Websocket server may bedelivered from the PD to the CD app. The Websocket server is a server inthe PD and may perform the above-described operation. In someembodiments, in this process, the endpoint information of the web servermay be delivered from the PD to the CD app. The web server is a serverin the PD and may perform the above-described operation.

This discovery process may be equal to the above-described discoveryprocess. In some embodiments, the CD app may not be launched by the PD.The CD may multicast an M-SEARCH message. The PD, which has receivedthis message, may send a 200 OK message as a response. The header of the200 OK message may include the LOCATION URL information of the PD.

The CD app may request a device description from this Location URL. Thisrequest may be performed using an HTTP GET method. The PD or thecompanion manager of the PD, which has received this request, maytransmit a first response message to the CD app. Here, the firstresponse message may include URL information used as a web serverendpoint in a header thereof. Here, the endpoint of the web server maymean a service URL provided by the above-described web server.

The companion manager of the PD may receive an application informationrequest from the CD app. The CD app may request application informationfrom the received URL. The companion module may transmit a secondresponse message as a response. The second response message may includeURL information used as the endpoint of the Websocket server in a bodythereof. The companion manager may correspond to the above-described CDmanager.

The present embodiment may correspond to the embodiment, in which the PDprovides an HTTP based web server and a Websocket based server, amongthe above-described embodiments. Particularly, the present embodimentmay correspond to an embodiment in which only one companion service URLis provided as an HTTP service URL and one companion endpoint and oneapp-to-app endpoint are provided as a Websocket server endpoint. Here,the Websocket companion endpoint may provide other functions excludingapp-to-app communication. Communication between the PD and the CD may beperformed by the web server or the Websocket server through division ofroles. For example, ESG delivery may be performed by the web server andservice and content identification, emergency alert (EA) messagedelivery and media playback information delivery may be performed by theWebsocket server. Media timeline information may be delivered throughthe web server and/or the Websocket server.

Thereafter, the companion manager of the PD may establish Websocketconnection between the Websocket server and the CD app. In this process,the above-described Websocket server endpoint may be used. A method ofestablishing Websocket connection (session) was described above indetail.

The Websocket server of the PD may receive a subscription message fromthe CD app. This subscription message may be delivered to theabove-described Websocket endpoint. This subscription message maysubscribe to a service identification notification service for receivinga service/content identification message including information derivedfrom the ESG. The service identification notification service may be aPD-CD notification service related to the above-describedservice/content identification. Through this process, the CD app maysubscribe to the notification service.

The reception component of the PD may receive ESG information through abroadcast network or broadband. The reception component may include oneor both of a tuner for receiving data through the broadcast network or anetwork interface for receiving data through broadband. The ESG mayinclude service guide information related to broadcast services providedby the PD.

The internal process of the PD may generate a service identificationmessage for a service identification notification service using thereceived ESG. This service identification message may correspond to theabove-described service/content identification message.

The Websocket server of the PD may deliver a service identificationmessage to the CD app which subscribes to the service identificationnotification service through Websocket connection. This delivery may beperformed in the form of a notification message of the above-describedWebsocket protocol. This notification may be performed when the ESGinformation is updated, when the ESG information is newly received orwhen information included in the service/content identification messageis changed. In addition, this notification may be periodically performedin some embodiments.

Here, the reception component, the Websocket server, the web server, theinternal processor, and the companion manager may be hardware elements.

In a method of processing a broadcast service at a PD according toanother embodiment of the present invention, the generating of theservice identification message may include including informationextracted from an ESG in the service identification message. The serviceidentification message may include at least one service element or atleast one content element.

The at least one service element may include service ID information,service type information, service name information or servicedescription information of the service fragment information of the ESGhaving service guide information of the broadcast service. That is, theservice element of the service identification message may be generatedusing the above-listed information of the service fragment informationof the ESG.

At least one content element may include content ID information, contentname information, content description information or content capabilityinformation of the content fragment information of the ESG havingservice guide information of the broadcast content. That is, the contentelement of the service identification message may be generated using theabove-listed information of the content fragment information of the ESG.

In the method of processing the broadcast service at the PD according toanother embodiment of the present invention, at least one contentelement may include at least one component element, at least one filecontent item element or a timeline element.

At least one component element may describe information on a componentincluded in the broadcast content. Here, the component may mean one ofan audio, video, closed caption or application component of thebroadcast content.

At least one file content item element may describe information on thefile content item included in the broadcast content. Here, the filecontent item may mean supplementary data of the broadcast content.

The timeline element may describe the current time information of thebroadcast content. In some embodiments, the temporal location of thebroadcast content at the current time may be indicated.

In the method of processing the broadcast service at the PD according toanother embodiment of the present invention, the generating of theservice identification message may further include including locationinformation in the service identification message. Here, the locationinformation may mean URL information for acquiring the file content itemor the component from the PD at the CD.

First URL information for enabling the CD app to access the componentmay be included in the above-described at least one component element.Second URL information for enabling the CD app to access the filecontent item may be included in the above-described at least one filecontent item element.

The method of processing the broadcast service at the PD according toanother embodiment of the present invention may include receiving anHTTP GET message for requesting the component or the file content itemthrough the first URL or second URL from the CD app and delivering therequested component or the file content item to the CD app. This may beoperation related to communication for service/show/segment datadelivery.

In the method of processing the broadcast service at the PD according toanother embodiment of the present invention, the PD may further providethe web server endpoint of the PD to the CD app in the discoveryprocess. This was described in the discovery process. In the method ofprocessing the broadcast service at the PD, the PD may receive the HTTPGET message from the CD app through the web server endpoint. This HTTPGET message may individually request the information corresponding tothe above-described service identification message.

This HTTP GET message may request at least one of a service element of acurrent broadcast service among the service elements, a componentelement of a currently available component among the component elements,or a file content item element of a currently available file contentitem among the file content item elements of the above-described serviceidentification message. The PD may deliver the information requested bythe HTTP GET message to the CD app. This process may be related tocommunication for current service information delivery.

In the method of processing the broadcast service at the PD according toanother embodiment of the present invention, the PD may receive an HTTPGET message from the CD app through the web server endpoint. This HTTPGET message may request ESG information in various formats. This HTTPGET message may request at least one of ESG information of a broadcastservice currently provided by the PD, ESG information of broadcastcontent currently provided by the PD or full ESG information ofavailable broadcast services. The PD may deliver the informationrequested by the HTTP GET message to the CD app. This process may berelated to communication for ESG information delivery.

A method of processing a broadcast service at a CD according to oneembodiment of the present invention will be described. This method isnot shown in the drawing.

The method of processing the broadcast service at the CD according tothe embodiment of the present invention, a launcher of the CD launchingan app of the CD, the app of the CD performing a discovery process witha PD using a network interface of the CD, the app of the CD establishingWebsocket connection with a Websocket server of the PD using a Websocketclient of the CD, the CD app transmitting a subscription message forreceiving a service/content identification message using the Websocketclient of the CD to subscribe to the service, and/or the CD appreceiving a service identification service using the Websocket client ofthe CD. The discovery process between the CD app and the PD may beperformed by the companion module of the CD. The CD app may request adevice description using the companion module, request applicationinformation from the above-described endpoints, and acquire responses tothe requests. In addition, the CD app may send an HTTP request/responseto the web server of the PD using the network interface of the CDaccording to situation.

The methods of processing the broadcast service at the CD according tothe embodiments of the present invention may correspond to the methodsof processing the broadcast service at the PD according to theabove-described embodiments of the present invention. The methods ofprocessing the broadcast service at the CD may be performed by hardwareelements (e.g., the companion module, the launcher, the Websocketclient, the network interface, etc.) corresponding to the hardwareelements used in the method of processing the broadcast service at thePD. The method of processing the broadcast service at the CD may haveembodiments corresponding to the embodiments of the method of theprocessing the broadcast service at the PD.

The above-described steps may be omitted or replaced by other steps ofperforming similar/equal operations in some embodiments.

FIG. 26 is a diagram showing a broadcast reception apparatus operatingas a PD according to an embodiment of the present invention.

The broadcast reception apparatus operating as the PD according to theembodiment of the present invention may include the above-describedcompanion manager, the Websocket server, the web server, the receptioncomponent and the processor (internal processor). The blocks and moduleswere described above.

The broadcast reception apparatus operating as the PD according to theembodiment of the present invention and the modules and blocks includedtherein may perform the embodiments of the method of processing thebroadcast service at the PD of the present invention.

A device operating as the CD according to the embodiment of the presentinvention will be described. This device is not shown in the drawing.

The device operating as the CD according to the embodiment of thepresent invention may include the above-described companion module, thelauncher, the Websocket client and/or the network interface. The blocksand modules were described above.

The device operating as the CD according to the embodiment of thepresent invention and the modules/blocks included therein may performthe embodiments of the method of processing the broadcast service at theCD of the present invention.

The blocks/modules included in the device may be hardware elements forperforming consecutive processes stored in a memory.

The above-described modules may be omitted or replaced by other modulesfor performing similar/equal operations in some embodiments.

Modules or units may be processors executing consecutive processesstored in a memory (or a storage unit). The steps described in theaforementioned embodiments can be performed by hardware/processors.Modules/blocks/units described in the above embodiments can operate ashardware/processors. The methods proposed by the present invention canbe executed as code. Such code can be written on a processor-readablestorage medium and thus can be read by a processor provided by anapparatus.

While the embodiments have been described with reference to respectivedrawings for convenience, embodiments may be combined to implement a newembodiment. In addition, designing computer-readable recording mediastoring programs for implementing the aforementioned embodiments iswithin the scope of the present invention.

The apparatus and method according to the present invention are notlimited to the configurations and methods of the above-describedembodiments and all or some of the embodiments may be selectivelycombined to obtain various modifications.

The methods proposed by the present invention may be implemented asprocessor-readable code stored in a processor-readable recording mediumincluded in a network device. The processor-readable recording mediumincludes all kinds of recording media storing data readable by aprocessor. Examples of the processor-readable recording medium include aROM, a RAM, a CD-ROM, a magnetic tape, a floppy disk, an optical datastorage device and the like, and implementation as carrier waves such astransmission over the Internet. In addition, the processor-readablerecording medium may be distributed to computer systems connectedthrough a network, stored and executed as code readable in a distributedmanner.

Although the preferred embodiments of the present invention have beendisclosed for illustrative purposes, those skilled in the art willappreciate that various modifications, additions and substitutions arepossible, without departing from the scope and spirit of the inventionas disclosed in the accompanying claims. Such modifications should notbe individually understood from the technical spirit or prospect of thepresent invention.

Both apparatus and method inventions are mentioned in this specificationand descriptions of both the apparatus and method inventions may becomplementarily applied to each other.

Those skilled in the art will appreciate that the present invention maybe carried out in other specific ways than those set forth hereinwithout departing from the spirit and essential characteristics of thepresent invention. Therefore, the scope of the invention should bedetermined by the appended claims and their legal equivalents, not bythe above description, and all changes coming within the meaning andequivalency range of the appended claims are intended to be embracedtherein.

In the specification, both the apparatus invention and the methodinvention are mentioned and description of both the apparatus inventionand the method invention can be applied complementarily.

MODE FOR INVENTION

Various embodiments have been described in the best mode for carryingout the invention.

INDUSTRIAL APPLICABILITY

The present invention is applied to broadcast signal providing fields.

Various equivalent modifications are possible within the spirit andscope of the present invention, as those skilled in the relevant artwill recognize and appreciate. Accordingly, it is intended that thepresent invention cover the modifications and variations of thisinvention provided they come within the scope of the appended claims andtheir equivalents.

1.-14. (canceled)
 15. A method of processing a broadcast service at aPrimary Device (PD), the method comprising: performing a discoveryprocess with a Companion Device (CD) application running in a CD bydelivering a WebSocket endpoint of a WebSocket server in the PD;establishing a WebSocket connection between the WebSocket server and theCD application using the WebSocket endpoint; receiving a subscriptionmessage for a PD-CD service, the PD-CD service for notifying the CDapplication with information about a broadcast service and a broadcastcontent; receiving an Electronic Service Guide (ESG) through a broadcastnetwork or broadband; generating a service identification message forthe PD-CD service using information in the ESG; and delivering, throughthe WebSocket connection, the service identification message to the CDapplication subscribing to the PD-CD service.
 16. The method accordingto claim 15, wherein the generating a service identification messagefurther includes: obtaining information from a Service fragment and aContent fragment of the ESG, and generating the service identificationmessage having a service element and a content element by using theinformation obtained from the ESG, wherein the service element includesservice ID information, service type information, service nameinformation and service description information, wherein the informationin the service element has values as specified in the Service fragmentof the ESG, and wherein the content element includes content IDinformation, content name information, content description informationand content capability information, wherein the information in thecontent element has values as specified in the Content fragment of theESG.
 17. The method according to claim 16, wherein the content elementincludes a component element, a file content item element and a timelineelement, wherein the component element includes information describing acontinuous component of the broadcast content, wherein the file contentitem element includes information describing a file content item of thebroadcast content, the file content item having supplementary data ofthe broadcast content, and wherein the timeline element includesinformation about current time location for the broadcast content. 18.The method according to claim 17, wherein the component element furtherincludes a first Uniform Resource Locator (URL) for enabling the CDapplication to access the continuous component, and wherein the filecontent item element further includes a second URL for enabling the CDapplication to access the file content item.
 19. The method according toclaim 18, the method further comprising: receiving an HTTP GET messagefor requesting the continuous component or the file content item fromthe CD application through the first URL or the second URL; anddelivering the requested continuous component or file content item tothe CD application.
 20. The method according to claim 18, the methodfurther comprising: receiving, from the CD application through a webserver endpoint, an HTTP GET message for requesting a service elementfor a current broadcast service, a component element for a currentlyavailable continuous component, or a file content item element for acurrently available file content item; and delivering informationrequested by the HTTP GET message to the CD application, wherein the webserver endpoint is delivered from the PD to the CD application duringthe discovery process.
 21. The method according to claim 18, the methodfurther comprising: receiving, from the CD application through a webserver endpoint, an HTTP GET message for requesting ESG information fora current broadcast service, ESG information for a current broadcastcontent or full ESG information for available broadcast services; anddelivering the requested ESG information to the CD application.
 22. Abroadcast reception apparatus operating as a Primary Device (PD),comprising: a companion manager configured to perform a discoveryprocess with a Companion Device (CD) application running in a CD bydelivering a WebSocket endpoint of a WebSocket server in the PD, whereinthe companion manager is further configured to establish a WebSocketconnection between the WebSocket server and the CD application using theWebSocket endpoint; a Websocket server configured to receive asubscription message for a PD-CD service, the PD-CD service fornotifying the CD application with information about a broadcast serviceand a broadcast content; a receiver configured to receive an ElectronicService Guide (ESG) through a broadcast network or broadband; and aprocessor configured to generate a service identification message forthe PD-CD service using information in the ESG, wherein the WebSocketserver is further configured to deliver the service identificationmessage to the CD application subscribing to the PD-CD service.
 23. Thebroadcast reception apparatus according to claim 22, wherein, togenerate the service identification message, the processor is furtherconfigured to: obtain information from a Service fragment and a Contentfragment of the ESG, and generate the service identification messagehaving a service element and a content element by using the informationobtained from the ESG, wherein the service element includes service IDinformation, service type information, service name information andservice description information, wherein the information in the serviceelement has values as specified in the Service fragment of the ESG, andwherein the content element includes content ID information, contentname information, content description information and content capabilityinformation, wherein the information in the content element has valuesas specified in the Content fragment of the ESG.
 24. The broadcastreception apparatus according to claim 23, wherein the content elementincludes a component element, a file content item element and a timelineelement, wherein the component element includes information describing acontinuous component of the broadcast content, wherein the file contentitem element includes information describing a file content item of thebroadcast content, the file content item having supplementary data ofthe broadcast content, and wherein the timeline element includesinformation about current time location for the broadcast content. 25.The broadcast reception apparatus according to claim 24, wherein thecomponent element further includes a first Uniform Resource Locator(URL) for enabling the CD application to access the continuouscomponent, and wherein the file content item element further includes asecond URL for enabling the CD application to access the file contentitem.
 26. The broadcast reception apparatus according to claim 25, theapparatus further comprising: a web server configured to receive an HTTPGET message for requesting the continuous component or the file contentitem from the CD application through the first URL or the second URL,and wherein the web server is further configured to deliver therequested continuous component or file content item to the CDapplication.
 27. The broadcast reception apparatus according to claim26, wherein the web server is further configured to: receive, from theCD application through a web server endpoint, an HTTP GET message forrequesting a service element for a current broadcast service, acomponent element for a currently available component, or a file contentitem element for a currently available file content item, and deliverinformation requested by the HTTP GET message to the CD application,wherein the web server endpoint is delivered from the PD to the CDapplication during the discovery process.
 28. The broadcast receptionapparatus according to claim 27, wherein the web server is furtherconfigured to: receive, from the CD application through a web serverendpoint, an HTTP GET message for requesting ESG information for acurrent broadcast service, ESG information for a current broadcastcontent or full ESG information for available broadcast services, anddeliver the requested ESG information to the CD application.